TWI523247B - Solar cell and module comprising the same - Google Patents
Solar cell and module comprising the same Download PDFInfo
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- TWI523247B TWI523247B TW102130794A TW102130794A TWI523247B TW I523247 B TWI523247 B TW I523247B TW 102130794 A TW102130794 A TW 102130794A TW 102130794 A TW102130794 A TW 102130794A TW I523247 B TWI523247 B TW I523247B
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Description
本發明是有關於一種太陽能電池及其模組，特別是指一種背接觸太陽能電池及其模組。 The invention relates to a solar cell and a module thereof, in particular to a back contact solar cell and a module thereof.
參閱圖1，為一種已知的指叉式背接觸(Interdigitated Back Contact，簡稱IBC)太陽能電池，通常包含：一基板91、分別位於該基板91的相反側的一抗反射層92與一鈍化層93、至少一第一電極94，以及至少一第二電極95。 Referring to FIG. 1 , a known interdigitated back contact (IBC) solar cell generally includes a substrate 91 , an anti-reflection layer 92 and a passivation layer respectively on opposite sides of the substrate 91 . 93. At least one first electrode 94, and at least one second electrode 95.
該基板91為n型半導體基板，並包括一供該抗反射層92配置且受光的正面911、一與該正面911相反且供該鈍化層93配置的背面912、一位於該正面911處且摻雜濃度大於該基板91的前表面電場部913，以及位於該背面912處且彼此間隔的至少一射極部914與至少一背表面電場部915。該第一電極94位於該鈍化層93上並可穿過該鈍化層93而連接該射極部914，該第二電極95位於該鈍化層93上並可穿過該鈍化層93而連接該背表面電場部915。 The substrate 91 is an n-type semiconductor substrate, and includes a front surface 911 configured to receive and receive the anti-reflective layer 92, a back surface 912 opposite to the front surface 911 and disposed on the passivation layer 93, and a front surface 911 and a blend The impurity concentration is greater than the front surface electric field portion 913 of the substrate 91, and at least one emitter portion 914 and at least one back surface electric field portion 915 located at the back surface 912 and spaced apart from each other. The first electrode 94 is located on the passivation layer 93 and can be connected to the emitter portion 914 through the passivation layer 93. The second electrode 95 is located on the passivation layer 93 and can pass through the passivation layer 93 to connect the back electrode. Surface electric field portion 915.
該背接觸太陽能電池的主要特色在於：該第一電極94與該第二電極95都位於該基板91的背面912，而 該正面911處未設置任何電極，所以可增加該正面911可受光的面積而提升入光量。又當光線經該太陽能電池的正面911進入該基板91內時，會在該基板91內產生光生載子(即電子與電洞)，其中，若載子生成時的位置越靠近該正面911，即相對地較遠離該背面912時，意味著載子至該背面912的傳輸路徑(Travelling Length)會較長，如此載子在傳導過程中將有較高的可能性被複合(Recombination)或因雜質之關係被捕捉而無法被使用，並導致漏電流(Leakage Current)發生。 The main feature of the back contact solar cell is that the first electrode 94 and the second electrode 95 are both located on the back surface 912 of the substrate 91, and No electrode is provided at the front surface 911, so that the amount of light that can be received by the front surface 911 can be increased. When light enters the substrate 91 through the front surface 911 of the solar cell, photo-generated carriers (i.e., electrons and holes) are generated in the substrate 91, wherein the position of the carrier when the carrier is generated is closer to the front surface 911. That is, relatively far away from the back surface 912, it means that the travel path of the carrier to the back surface 912 is longer, so that the carrier will have a higher probability of being recombined or caused during conduction. Impurity relationships are captured and cannot be used, and lead to leakage currents (Leakage Current).
因此，若能縮短該正面911與該背面912的距離以縮短載子的傳輸路徑，藉此增加載子進入該射極部914或該背表面電場部915的機會以增進載子收集效率，則將可進一步再提升該背接觸太陽能電池的光電轉換效率。然而，若為縮短該正面911與該背面912的距離而僅一味地減少該基板91之厚度，又可能會導致該基板91的厚度過薄而降低其結構強度，因而增加破片率。 Therefore, if the distance between the front surface 911 and the back surface 912 can be shortened to shorten the transmission path of the carrier, thereby increasing the chance of the carrier entering the emitter portion 914 or the back surface electric field portion 915 to improve the carrier collection efficiency, The photoelectric conversion efficiency of the back contact solar cell can be further improved. However, if the thickness of the substrate 91 is reduced only to shorten the distance between the front surface 911 and the back surface 912, the thickness of the substrate 91 may be too thin to reduce the structural strength, thereby increasing the chipping rate.
因此，本發明之目的，即在提供一種可增加光利用率與載子收集效率，進而提升光電轉換效率的太陽能電池及其模組。 Accordingly, it is an object of the present invention to provide a solar cell and a module thereof that can increase light utilization efficiency and carrier collection efficiency, thereby improving photoelectric conversion efficiency.
於是，本發明太陽能電池，包含：一第一導電型的基板、至少一第一導電型摻雜區、至少一第二導電型摻雜區、至少一第一電極，以及至少一第二電極。 Therefore, the solar cell of the present invention comprises: a first conductivity type substrate, at least one first conductivity type doping region, at least one second conductivity type doping region, at least one first electrode, and at least one second electrode.
該基板包括一受光的正面，以及一相對於該正 面的背面，該正面具有數個朝該背面延伸且縱剖面呈多邊形的第一孔洞，所述多邊形由N個邊所構成且N大於3。該第一導電型摻雜區位於該背面處，該第二導電型摻雜區位於該背面處且位置對應該數個第一孔洞，該第一電極位於該背面上並連接該第一導電型摻雜區，而該第二電極位於該背面上並連接該第二導電型摻雜區。 The substrate includes a light-receiving front surface, and a positive relative to the positive The back side of the face has a plurality of first holes extending toward the back face and having a polygonal cross section, the polygon being composed of N sides and N being greater than 3. The first conductive type doped region is located at the back surface, and the second conductive type doped region is located at the back surface and corresponding to the plurality of first holes, the first electrode is located on the back surface and is connected to the first conductive type a doped region, and the second electrode is located on the back surface and connected to the second conductive type doped region.
本發明太陽能電池模組，包含：一第一板材、一第二板材、至少一個如前述且設置於該第一板材與該第二板材間的太陽能電池，以及一位於該第一板材與該第二板材間並接觸該太陽能電池的封裝材。 The solar cell module of the present invention comprises: a first plate, a second plate, at least one solar cell disposed between the first plate and the second plate, and a first plate and the first plate The two sheets are in contact with the packaging material of the solar cell.
本發明之功效在於：透過在該正面形成所述第一孔洞之創新結構設計，除了可降低光反射以進一步地提升入光量與光使用率之外，由於所述第一孔洞是朝該背面延伸，可縮短該正面與該背面之間的距離，藉此縮短少數載子的傳輸路徑以增加少數載子進入該第二導電型摻雜區的機會，因而可降低載子複合的機率並增進載子收集效率，故能提升該太陽能電池的光電轉換效率。 The effect of the present invention is that, through the innovative structural design of forming the first hole in the front surface, in addition to reducing light reflection to further increase the amount of light incident and light usage, since the first hole is extended toward the back surface The distance between the front side and the back side can be shortened, thereby shortening the transmission path of a minority carrier to increase the chance of a minority carrier entering the second conductive type doped area, thereby reducing the probability of carrier recombination and enhancing the load. The efficiency of the sub-collection can improve the photoelectric conversion efficiency of the solar cell.
11‧‧‧第一板材 11‧‧‧ first plate
12‧‧‧第二板材 12‧‧‧Second plate
13‧‧‧太陽能電池 13‧‧‧Solar battery
14‧‧‧封裝材 14‧‧‧Package
15‧‧‧焊帶導線 15‧‧‧welding wire
2‧‧‧基板 2‧‧‧Substrate
21‧‧‧前表面電場區 21‧‧‧ front surface electric field
22‧‧‧第一導電型摻雜區 22‧‧‧First Conductive Doped Area
23‧‧‧第二導電型摻雜區 23‧‧‧Second Conductive Doped Area
24‧‧‧間隔區 24‧‧‧ interval zone
31‧‧‧介電層 31‧‧‧Dielectric layer
32‧‧‧抗反射層 32‧‧‧Anti-reflective layer
41‧‧‧第一電極 41‧‧‧First electrode
42‧‧‧第二電極 42‧‧‧second electrode
5‧‧‧正面 5‧‧‧ positive
51‧‧‧第一孔洞 51‧‧‧First hole
52‧‧‧第一表面 52‧‧‧ first surface
521‧‧‧側面 521‧‧‧ side
522‧‧‧底面 522‧‧‧ bottom
523‧‧‧金字塔結構 523‧‧‧ pyramid structure
524‧‧‧金字塔結構 524‧‧‧ Pyramid structure
53‧‧‧粗糙面部 53‧‧‧Rough face
531‧‧‧金字塔結構 531‧‧‧ Pyramid structure
54‧‧‧第二孔洞 54‧‧‧Second hole
55‧‧‧第二表面 55‧‧‧second surface
551‧‧‧側面 551‧‧‧ side
552‧‧‧底面 552‧‧‧ bottom
56‧‧‧第三孔洞 56‧‧‧ third hole
57‧‧‧第三表面 57‧‧‧ third surface
571‧‧‧側面 571‧‧‧ side
572‧‧‧底面 572‧‧‧ bottom
58‧‧‧金字塔結構 58‧‧‧ pyramid structure
59‧‧‧第四孔洞 59‧‧‧Fourth hole
6‧‧‧背面 6‧‧‧ Back
d1‧‧‧孔徑 D1‧‧‧ aperture
d2‧‧‧深度 D2‧‧ depth
d3‧‧‧高度 D3‧‧‧ Height
d4‧‧‧間距 D4‧‧‧ spacing
S01~S05‧‧‧步驟 S01~S05‧‧‧Steps
本發明之其他的特徵及功效，將於參照圖式的實施方式中清楚地呈現，其中：圖1是一種已知的背接觸太陽能電池的剖視示意圖；圖2是本發明太陽能電池模組之一第一較佳實施例之一局部剖視示意圖；圖3是該第一較佳實施例之一太陽能電池之一俯視示 意圖，圖中省略該太陽能電池之一抗反射層，並顯示該太陽能電池之一基板之數個第一導電型摻雜區之形貌；圖4是該太陽能電池之一側視剖視示意圖，並顯示該太陽能電池沿著圖3的A-A線所示位置之剖視結構，且圖中繪出該太陽能電池之抗反射層；圖5是一類似圖3的示意圖，顯示所述第一導電型摻雜區之另一種實施態樣；圖6是本發明太陽能電池之製造方法之一第一較佳實施例之一步驟流程方塊圖；圖7是該製造方法之第一較佳實施例之一步驟流程示意圖；圖8是一側視剖視示意圖，顯示本發明太陽能電池模組之一第二較佳實施例之一太陽能電池的剖視結構；圖9是本發明太陽能電池之製造方法之一第二較佳實施例之一步驟流程示意圖；圖10是一側視剖視示意圖，顯示本發明太陽能電池模組之一第三較佳實施例之一太陽能電池的剖視結構；圖11是一步驟流程示意圖，顯示本發明太陽能電池之製造方法之一第三較佳實施例的其中幾個步驟流程；圖12是一側視剖視示意圖，顯示本發明太陽能電池模組之一第四較佳實施例之一太陽能電池的剖視結構；圖13是圖12的局部放大圖，顯示該太陽能電池之一正面的細部結構；圖14是一步驟流程示意圖，顯示本發明太陽能電池之 製造方法之一第四較佳實施例的其中幾個步驟流程；圖15是一側視剖視示意圖，顯示本發明太陽能電池模組之一第五較佳實施例之一太陽能電池的剖視結構；及圖16是一步驟流程示意圖，顯示本發明太陽能電池之製造方法之一第五較佳實施例的其中幾個步驟流程。 Other features and effects of the present invention will be apparent from the following description of the drawings, wherein: FIG. 1 is a schematic cross-sectional view of a known back contact solar cell; FIG. 2 is a solar cell module of the present invention. A schematic cross-sectional view of a first preferred embodiment; FIG. 3 is a top plan view of one of the solar cells of the first preferred embodiment In the figure, one of the anti-reflection layers of the solar cell is omitted, and the topography of the plurality of first conductive type doped regions of one of the solar cells is shown; FIG. 4 is a side cross-sectional view of the solar cell. And showing the cross-sectional structure of the solar cell along the position indicated by the AA line in FIG. 3, and the anti-reflection layer of the solar cell is depicted in the figure; FIG. 5 is a schematic view similar to FIG. 3, showing the first conductivity type Another embodiment of the doped region; FIG. 6 is a block flow diagram of one of the first preferred embodiments of the method for fabricating the solar cell of the present invention; FIG. 7 is one of the first preferred embodiments of the manufacturing method. FIG. 8 is a side cross-sectional view showing a cross-sectional structure of a solar cell according to a second preferred embodiment of the solar cell module of the present invention; FIG. 9 is a manufacturing method of the solar cell of the present invention; FIG. 10 is a side cross-sectional view showing a cross-sectional view of a solar cell according to a third preferred embodiment of the solar cell module of the present invention; FIG. 11 is a Step flow BRIEF DESCRIPTION OF THE DRAWINGS FIG. 12 is a side elevational cross-sectional view showing a fourth preferred embodiment of a solar cell module of the present invention. FIG. FIG. 13 is a partial enlarged view of FIG. 12, showing a detailed structure of a front surface of the solar cell; FIG. 14 is a schematic flow chart showing a step of the solar cell of the present invention. One of the steps of the fourth preferred embodiment of the manufacturing method; FIG. 15 is a side cross-sectional view showing the cross-sectional structure of a solar cell according to a fifth preferred embodiment of the solar cell module of the present invention; And FIG. 16 is a schematic flow chart showing the steps of a fifth preferred embodiment of the solar cell manufacturing method of the present invention.
在本發明被詳細描述之前，應當注意在以下的說明內容中，類似的元件是以相同的編號來表示。 Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.
參閱圖2，本發明太陽能電池模組之一第一較佳實施例包含：上下相對間隔設置的一第一板材11與一第二板材12、數個陣列式地排列於該第一板材11與該第二板材12之間的太陽能電池13，以及一位於該第一板材11與該第二板材12之間且接觸該數個太陽能電池13的封裝材14。當然在實施上，該太陽能電池模組可以僅包含一太陽能電池13。 Referring to FIG. 2, a first preferred embodiment of the solar cell module of the present invention comprises: a first plate 11 and a second plate 12 disposed at an upper and lower interval, and a plurality of arrays arranged on the first plate 11 and The solar cell 13 between the second sheets 12 and a package 14 between the first sheet 11 and the second sheet 12 and contacting the plurality of solar cells 13. Of course, in practice, the solar cell module may include only one solar cell 13.
在本實施例中，該第一板材11與該第二板材12的材料在實施上沒有特殊限制，可使用玻璃或塑膠板材，而且位於該太陽能電池13之受光側的板材必須可透光。該封裝材14的材質例如可透光的乙烯醋酸乙烯共聚物(EVA)，或其他可用於太陽能電池模組封裝的相關材料，並不限於本實施例的舉例。此外，該數個太陽能電池13彼此之間可透過數個焊帶導線(Ribbon)15電連接。此外，由於該數個太陽能電池13的結構都相同，以下僅以其中一個為例進行說明。當然，在一模組中的該數個太陽能電池13 的結構不以相同為絕對之必要。 In the present embodiment, the material of the first plate 11 and the second plate 12 is not particularly limited, and a glass or plastic plate may be used, and the plate on the light receiving side of the solar cell 13 must be transparent. The material of the encapsulant 14 is, for example, a light transmissive ethylene vinyl acetate copolymer (EVA), or other related materials usable for the solar cell module package, and is not limited to the examples of the embodiment. Further, the plurality of solar cells 13 are electrically connected to each other through a plurality of ribbon wires 15. In addition, since the structures of the several solar cells 13 are the same, only one of them will be described below as an example. Of course, the plurality of solar cells 13 in a module The structure is not absolutely necessary for the same.
參閱圖3、4，本實施例的太陽能電池13為背接觸太陽能電池的形式，並包含：一第一導電型的基板2、一前表面電場區21、數個第一導電型摻雜區22、一第二導電型摻雜區23、數個間隔區24、一介電層31、數個第一電極41，以及一第二電極42。本實施例所述之第一導電型與第二導電型分別為n型與p型，但實施時也可以相反。 Referring to FIGS. 3 and 4, the solar cell 13 of the present embodiment is in the form of a back contact solar cell, and includes: a first conductivity type substrate 2, a front surface electric field region 21, and a plurality of first conductivity type doping regions 22 a second conductive type doped region 23, a plurality of spacers 24, a dielectric layer 31, a plurality of first electrodes 41, and a second electrode 42. The first conductivity type and the second conductivity type described in this embodiment are respectively n-type and p-type, but may be reversed in implementation.
本實施例的基板2為n型的單晶矽基板，實施上亦可為多晶矽基板。該基板2包括一受光的正面5，以及一相對於該正面5的背面6，其中，該正面5與該背面6之間並無貫穿。該正面5具有數個直線地朝該背面6延伸且縱剖面呈多邊形的第一孔洞51，以及數個分別圍繞界定出該數個第一孔洞51的第一表面52，所述多邊形由N個邊所構成且N大於3。 The substrate 2 of the present embodiment is an n-type single crystal germanium substrate, and may be a polycrystalline germanium substrate. The substrate 2 includes a light-receiving front surface 5 and a back surface 6 opposite the front surface 5, wherein there is no penetration between the front surface 5 and the back surface 6. The front surface 5 has a plurality of first holes 51 extending linearly toward the back surface 6 and having a polygonal cross section, and a plurality of first surfaces 52 respectively defining the plurality of first holes 51, the polygons being N The edge is composed and N is greater than 3.
該數個第一孔洞51彼此間隔且為二維排列，此外於實施上，亦可以二維陣列式之型態來排列，且該數個第一孔洞51彼此間可為獨立間隔而無連通之形式，或是依設計而使其中幾個的第一孔洞51彼此間相互連通。又在本實施例中，每一第一孔洞51的縱剖面皆呈矩形，且與該正面5成垂直之型態，但於實施上不限於此，只要縱剖面之形狀是由大於3個邊所構成之多邊形即可，該數個第一孔洞51各自的縱剖面亦可不相同來作搭配設計。 The plurality of first holes 51 are spaced apart from each other and arranged in two dimensions. In addition, in practice, the first holes 51 may be arranged in a two-dimensional array, and the plurality of first holes 51 may be independently spaced from each other without being connected. Forms, or by design, several of the first holes 51 are in communication with each other. In this embodiment, the longitudinal section of each of the first holes 51 is rectangular and perpendicular to the front surface 5, but is not limited thereto, as long as the shape of the longitudinal section is greater than 3 sides. The polygonal shape may be formed, and the longitudinal cross-sections of the plurality of first holes 51 may be different.
對應地，每一第一表面52具有一平行該背面6 的底面522，以及一垂直且圍繞地連接該底面522的側面521。在實施上，該數個第一孔洞51的孔徑d1為5~40μm，深度d2為5~40μm。較佳地，孔徑d1較小且深度d2較大時，抗反射與提供載子傳導之效果將隨之提昇，例如深度d2與孔徑d1之比值大於1.5時會有較佳效果，故於實施上，可至少選擇以深度d2為30μm以及孔徑d1為20μm之形式來實施。在該正面5上每1mm2有500~40000個第一孔洞51，並且相鄰的該兩個第一孔洞51之間距d4至少5μm。 Correspondingly, each of the first surfaces 52 has a bottom surface 522 that is parallel to the back surface 6, and a side surface 521 that is perpendicularly and circumferentially coupled to the bottom surface 522. In practice, the plurality of first holes 51 have a hole diameter d1 of 5 to 40 μm and a depth d2 of 5 to 40 μm. Preferably, when the aperture d1 is small and the depth d2 is large, the anti-reflection and the effect of providing carrier conduction are improved. For example, when the ratio of the depth d2 to the aperture d1 is greater than 1.5, the effect is better. It can be selected to be at least selected in the form of a depth d2 of 30 μm and a pore diameter d1 of 20 μm. There are 500 to 40,000 first holes 51 per 1 mm 2 on the front surface 5, and the adjacent first holes 51 are at least 5 μm apart from d4.
此外，該正面5還可具有數個彼此間隔且位置對應該數個第一導電型摻雜區22與該數個間隔區24的粗糙面部53，每一粗糙面部53具有數個彼此相連的金字塔結構531，藉此可提高入光量。在實施上，每一個金字塔結構531的高度d3不需限制，其一般為1~10μm，較佳為3~5μm。需要說明的是，本實施例所述的金字塔結構531，主要是描述四角錐狀結構，前述四角錐狀結構是由一呈四邊形的基面、一位於該基面上方的頂點，以及四條連接該頂點與該基面的四個角的稜線所構成。當然，該基面可為長方形、正方形、菱形等四邊形，而該四條稜線可為直線或凹弧的曲線，不需限制。 In addition, the front surface 5 may further have a plurality of rough surface portions 53 spaced apart from each other and corresponding to the plurality of first conductive type doping regions 22 and the plurality of spacer regions 24, each of the rough surface portions 53 having a plurality of pyramids connected to each other Structure 531, whereby the amount of light incident can be increased. In practice, the height d3 of each pyramid structure 531 is not limited, and is generally 1 to 10 μm, preferably 3 to 5 μm. It should be noted that the pyramid structure 531 described in this embodiment mainly describes a quadrangular pyramid structure, wherein the quadrangular pyramid structure is composed of a quadrilateral base surface, a vertex located above the base surface, and four connections. The vertices are formed by the ridges of the four corners of the base. Of course, the base surface may be a rectangle such as a rectangle, a square, a diamond, or the like, and the four ridge lines may be a straight line or a concave arc curve, and need not be limited.
本實施例的前表面電場區21位於該正面5處之內，並沿著該數個第一表面52與該數個粗糙面部53配置。該前表面電場區21為n+型半導體，且其摻雜濃度大於該基板2之摻雜濃度，藉此形成正面電場結構(Front-Side Field，簡稱FSF)以提升載子收集效率及光電轉換效率。 The front surface electric field region 21 of the present embodiment is located within the front surface 5 and is disposed along the plurality of first surfaces 52 and the plurality of rough surface portions 53. The front surface electric field region 21 is an n + -type semiconductor, and its doping concentration is greater than the doping concentration of the substrate 2, thereby forming a front-side electric field structure (Front-Side Field, FSF for short) to improve carrier collection efficiency and photoelectric conversion. effectiveness.
本實施例的第一導電型摻雜區22位於該背面6處之內，且位置對應該正面5之粗糙面部53，該第一導電型摻雜區22是藉由擴散製程(例如磷擴散)或其他的摻雜方式使該基板2局部形成重摻雜的n++型半導體，且其摻雜濃度大於該基板2的摻雜濃度。 The first conductive type doped region 22 of the present embodiment is located inside the back surface 6 and is located corresponding to the rough surface portion 53 of the front surface 5, and the first conductive type doped region 22 is diffused by a diffusion process (for example, phosphorus diffusion). Or other doping manner causes the substrate 2 to partially form a heavily doped n ++ type semiconductor, and its doping concentration is greater than the doping concentration of the substrate 2.
本實施例的第二導電型摻雜區23位於該背面6處之內，且位置對應該數個第一孔洞51，其中該數個第一孔洞51的平均深度大於該數個粗糙面部53的平均深度。該第二導電型摻雜區23是藉由擴散製程(例如硼擴散)或其他的摻雜方式使該基板2局部形成重摻雜的p+型半導體。 The second conductive type doped region 23 of the present embodiment is located within the back surface 6 and corresponds to the plurality of first holes 51, wherein the average depth of the plurality of first holes 51 is greater than the plurality of rough portions 53 Average depth. The second conductive type doping region 23 partially forms the heavily doped p + -type semiconductor by the diffusion process (for example, boron diffusion) or other doping methods.
進一步說明的是，若該基板2使用p型半導體基板時，該前表面電場區21就會製作成摻雜濃度大於前述基板2的p+型半導體，該數個第一導電型摻雜區22就會製作成摻雜濃度大於前述基板2之p++型半導體，而該第二導電型摻雜區23則製作成n+型半導體。 Further, if the substrate 2 uses a p-type semiconductor substrate, the front surface electric field region 21 is formed as a p + -type semiconductor having a doping concentration greater than that of the substrate 2, and the plurality of first conductive type doped regions 22 A p ++ type semiconductor having a doping concentration higher than that of the substrate 2 is formed, and the second conductive type doped region 23 is formed as an n + type semiconductor.
該數個間隔區24位於該背面6處且分別位於該數個第一導電型摻雜區22與該第二導電型摻雜區23之間，用於隔開該數個第一導電型摻雜區22與該第二導電型摻雜區23，以避免寄生分流(Parasitic Shunting)現象而產生漏電流(Leakage Current)。實際上，利用擴散製程製作該數個第一導電型摻雜區22與該第二導電型摻雜區23時，可透過適當的製程控制，使該數個第一導電型摻雜區22與該第二導電型摻雜區23間隔，則該數個第一導電型 摻雜區22與該第二導電型摻雜區23之間未額外進行擴散製程的區域就成為該數個間隔區24。當然，該數個間隔區24亦可透過雷射製程剝蝕而形成明確內凹狀之分隔結構(圖未示)，以避免擴散製程中於該數個第一導電型摻雜區22與該第二導電型摻雜區23之交界地帶可能餘留之摻雜雜質，從而防止漏電流之產生。 The plurality of spacers 24 are located at the back surface 6 and are respectively located between the plurality of first conductive type doped regions 22 and the second conductive type doped regions 23 for spacing the plurality of first conductive type doping The impurity region 22 and the second conductivity type doping region 23 prevent leakage current (Leakage Current) from parasitic shunting. In fact, when the plurality of first conductive type doped regions 22 and the second conductive type doped regions 23 are formed by a diffusion process, the plurality of first conductive type doped regions 22 can be made through appropriate process control. The second conductive type doped regions 23 are spaced apart, and the plurality of first conductive types are A region where the diffusion process is not additionally performed between the doping region 22 and the second conductivity type doping region 23 becomes the plurality of spacer regions 24. Of course, the plurality of spacers 24 can also be ablated by a laser process to form a well-concavely separated structure (not shown) to avoid the plurality of first conductive type doped regions 22 and the diffusion process in the diffusion process. The boundary between the two conductive type doping regions 23 may leave doping impurities, thereby preventing generation of leakage current.
需要說明的是，在本實施例中，該數個第一導電型摻雜區22是如圖3所示的點狀分佈之方式配置於該基板2之背面6處之內，而該數個間隔區24分別圍繞該數個第一導電型摻雜區22。因為本實施例採用n型基板，其少數載子為電洞，為進一步提昇少數載子之收集效果，從而將該第二導電型摻雜區23以如圖3所示地大面積分佈設置。當然，該太陽能電池13的第一導電型摻雜區22、第二導電型摻雜區23與間隔區24的結構不限於此，也可為如圖5所示的指叉式的結構。 It should be noted that, in this embodiment, the plurality of first conductive type doped regions 22 are disposed in the dot-like distribution as shown in FIG. 3, and are disposed in the back surface 6 of the substrate 2, and the plurality of The spacers 24 surround the plurality of first conductive type doping regions 22, respectively. Because the n-type substrate is used in this embodiment, a minority carrier is a hole, and the second conductive type doped region 23 is disposed in a large area as shown in FIG. 3 in order to further enhance the collection effect of the minority carriers. Of course, the structure of the first conductive type doped region 22, the second conductive type doped region 23, and the spacer region 24 of the solar cell 13 is not limited thereto, and may be an interdigitated structure as shown in FIG. 5.
請再參閱圖3、4，本實施例的介電層31位於該背面6，並且覆蓋於該數個第一導電型摻雜區22、該第二導電型摻雜區23與該數個間隔區24上。該介電層31的材料可為氧化物、氮化物或上述材料的組合，並用於鈍化、修補該基板2的表面以減少表面之懸鍵(Dangling Bond)與缺陷，從而可減少載子陷阱(Trap)及降低載子的表面複合速率(Surface Recombination Velocity，簡稱SRV)，以提升該太陽能電池13的光電轉換效率。此外，該前表面電場區21上還可設置一抗反射層32，其材料例如氮化矽(SiNx) 等，用於提升光線入射量以及降低載子的表面複合速率。不過在實施上，本發明不以設有該介電層31與該抗反射層32為絕對之必要。 Referring to FIGS. 3 and 4, the dielectric layer 31 of the present embodiment is located on the back surface 6 and covers the plurality of first conductive type doped regions 22, the second conductive type doped regions 23, and the plurality of spaces. On area 24. The material of the dielectric layer 31 may be an oxide, a nitride or a combination of the above materials, and is used for passivating and repairing the surface of the substrate 2 to reduce the Dangling Bond and defects of the surface, thereby reducing carrier traps ( Trap) and reducing the Surface Recombination Velocity (SRV) of the carrier to improve the photoelectric conversion efficiency of the solar cell 13. In addition, the front surface field region 32 may also be provided an anti-reflection layer 21 on which material such as silicon nitride (SiN x) and the like, for lifting and lowering the amount of light incident on the rate of surface recombination of carriers. However, in practice, the present invention is not essential to provide the dielectric layer 31 and the anti-reflective layer 32.
本實施例的第一電極41位於該背面6上並分別穿過該介電層31而連接該數個第一導電型摻雜區22，而本實施例的第二電極42位於該背面6上並穿過該介電層31而連接該第二導電型摻雜區23。 The first electrode 41 of the present embodiment is located on the back surface 6 and passes through the dielectric layer 31 to connect the plurality of first conductive type doped regions 22, and the second electrode 42 of the embodiment is located on the back surface 6. The second conductive type doped region 23 is connected through the dielectric layer 31.
需要說明的是，本實施例雖然以數個第一導電型摻雜區22、一個第二導電型摻雜區23及數個間隔區24為例進行說明，但實際上在一太陽能電池13中，第二導電型摻雜區23的數量可以為更多個，並以p-n-p-n之交錯方式重複排列配置，任一組相鄰的第一導電型摻雜區22與第二導電型摻雜區23之間即形成一個間隔區24。而且相對應地，第一電極41與粗糙面部53對應第一導電型摻雜區22的位置，而第二電極42與第一孔洞51則對應第二導電型摻雜區23的位置。此外，本發明也可以只針對其中一組第一導電型摻雜區22、第二導電型摻雜區23與間隔區24來進行改良。 It should be noted that, in this embodiment, a plurality of first conductive type doping regions 22, a second conductive type doping region 23, and a plurality of spacer regions 24 are taken as an example, but actually in a solar cell 13. The number of the second conductive type doped regions 23 may be more and arranged in a staggered manner in a pnpn manner, and any one of the adjacent first conductive type doped regions 22 and the second conductive type doped regions 23 may be alternately arranged. A spacer 24 is formed between them. Correspondingly, the first electrode 41 and the rough surface portion 53 correspond to the position of the first conductive type doping region 22, and the second electrode 42 and the first hole 51 correspond to the position of the second conductive type doping region 23. Furthermore, the present invention can also be modified only for one of the first conductive type doped regions 22, the second conductive type doped regions 23, and the spacers 24.
參閱圖4、6、7，本發明太陽能電池13的製造方法之一第一較佳實施例，包含： Referring to Figures 4, 6, and 7, a first preferred embodiment of a method of fabricating a solar cell 13 of the present invention comprises:
步驟S01：提供該單晶之矽基板2。 Step S01: providing the single crystal germanium substrate 2.
步驟S02：先在該基板2的正面5進行粗糙化處理，使該正面5形成凹凸不平的該數個粗糙面部53，在本實施例是使用含有氫氧化鉀(KOH)與異丙醇(IPA)的溶液蝕 刻該正面5。接著於該正面5進一步使用雷射以形成朝該背面6延伸的該數個第一孔洞51，一般而言以雷射加工所製得之孔洞的縱剖面不會呈三角形。除此之外，雷射加工之後，還可視情況使用蝕刻液(例如KOH)蝕刻該基板2形成有該數個第一孔洞51的部位，以去除因雷射所生成的損傷層。 Step S02: first roughening the front surface 5 of the substrate 2 so that the front surface 5 forms the uneven surface portions 53 of the unevenness. In this embodiment, potassium hydroxide (KOH) and isopropyl alcohol (IPA) are used. Solution etch Engraved the front 5. A laser is further used on the front side 5 to form the plurality of first holes 51 extending toward the back surface 6. Generally, the longitudinal cross-section of the holes made by laser processing does not have a triangular shape. In addition, after the laser processing, an etchant (for example, KOH) may be used to etch the portion of the substrate 2 where the plurality of first holes 51 are formed to remove the damaged layer formed by the laser.
需要說明的是，形成該數個第一孔洞51的手段還可使用溼蝕刻、蝕刻膠或機械式等方式，其中，就使用蝕刻膠之手段而言，可透過噴塗或網印等方式將蝕刻膠披覆於該正面5上，並以網印之方式具較佳之披覆位置精密度，至於機械式之手段例如可使用奈米或微米尺寸的鑽孔機，或者使用聚焦離子束或電子束而在該基板2上形成該數個第一孔洞51。 It should be noted that the means for forming the plurality of first holes 51 may also be performed by wet etching, etching glue or mechanical means, wherein the etching may be performed by means of spraying or screen printing. The glue is coated on the front surface 5 and has a better coverage precision in the form of screen printing. For mechanical means, for example, a nano or micro size drill can be used, or a focused ion beam or an electron beam can be used. The plurality of first holes 51 are formed on the substrate 2.
步驟S03：利用擴散製程分別在該基板2的背面6處之內形成該數個第一導電型摻雜區22與該第二導電型摻雜區23，並且該第二導電型摻雜區23之位置對應該數個第一孔洞51。當然，此步驟必須搭配相關遮罩以形成該數個第一導電型摻雜區22與該第二導電型摻雜區23。 Step S03: forming the plurality of first conductive type doping regions 22 and the second conductive type doping regions 23 in the back surface 6 of the substrate 2 by using a diffusion process, and the second conductive type doping region 23 The position corresponds to a plurality of first holes 51. Of course, this step must be accompanied by an associated mask to form the plurality of first conductive type doped regions 22 and the second conductive type doped regions 23.
步驟S04：先在該正面5處形成該前表面電場區21，接著在該正面5與該背面6上分別形成該抗反射層32與該介電層31。 Step S04: forming the front surface electric field region 21 at the front surface 5, and then forming the anti-reflection layer 32 and the dielectric layer 31 on the front surface 5 and the back surface 6, respectively.
步驟S05：分別在該基板2的背面6處形成該數個第一電極41與該第二電極42，使該數個第一電極41分別穿過該介電層31而連接該數個第一導電型摻雜區22， 而該第二電極42穿過該介電層31而連接該第二導電型摻雜區23。於實施上，可透過網版印刷電極漿料或透過電漿輔助化學氣相沉積法(PECVD)等方式形成該數個第一電極41與該第二電極42。 Step S05: forming the plurality of first electrodes 41 and the second electrodes 42 at the back surface 6 of the substrate 2, respectively, and connecting the plurality of first electrodes 41 through the dielectric layer 31 to connect the plurality of first electrodes Conductive doped region 22, The second electrode 42 is connected to the second conductive type doped region 23 through the dielectric layer 31. In practice, the plurality of first electrodes 41 and the second electrodes 42 may be formed by a screen printing electrode paste or by plasma assisted chemical vapor deposition (PECVD).
參閱圖2、3、4，在使用上，當光線照射在該太陽能電池13的正面5時，除了透過該抗反射層32與該正面5之粗糙面部53降低光反射以提升入光量之外，本實施例透過在該正面5形成該數個第一孔洞51，以及分別圍繞界定出該數個第一孔洞51的該數個第一表面52，前述結構也可降低光反射，因而更進一步地提升入光量與光使用率，這是因為該數個第一孔洞51的孔徑d1小於入射光之光波，因此入射光會受該數個第一孔洞51限制而難以反射逃逸。於實施時，原則上以孔徑d1較小且孔洞深度d2較深時效果為佳，例如可選擇以深度d2與孔徑d1之比值大於1.5以達較佳效果，故於實施上，可至少選擇以深度d2為30μm以及孔徑d1為20μm之形式來實施。在該正面5上每1mm2有500~40000個第一孔洞51，並且相鄰的該兩個第一孔洞51之間距d4至少5μm。 2, 3, and 4, in use, when light is incident on the front surface 5 of the solar cell 13, except that the light reflection is reduced by the anti-reflection layer 32 and the rough surface portion 53 of the front surface 5 to increase the amount of light incident, In the embodiment, by forming the plurality of first holes 51 on the front surface 5 and respectively surrounding the plurality of first surfaces 52 defining the plurality of first holes 51, the foregoing structure can also reduce light reflection, thereby further The amount of incident light and the light usage rate are increased because the apertures d1 of the plurality of first holes 51 are smaller than the light waves of the incident light, and thus the incident light is restricted by the plurality of first holes 51 to be difficult to reflect and escape. In practice, in principle, the effect is better when the aperture d1 is smaller and the hole depth d2 is deeper. For example, the ratio of the depth d2 to the aperture d1 may be selected to be greater than 1.5 for better effect, so in practice, at least The depth d2 was 30 μm and the aperture d1 was 20 μm. There are 500 to 40,000 first holes 51 per 1 mm 2 on the front surface 5, and the adjacent first holes 51 are at least 5 μm apart from d4.
除此之外，由於在該基板2內越靠近該正面5的部分所生成的載子數量越高，又因為本實施例的基板2為n型半導體基板，其主要載子為電子，少數載子為電洞，所以本實施例將該數個第一孔洞51設置於該第二導電型摻雜區23的上方，同時配合該數個第一孔洞51是朝該背面6延伸，使每一第一表面52的底面522也相對鄰近該 基板2的背面6，可縮短該數個第一表面52的底面522與該背面6之間的距離，以縮短少數載子傳輸到該第二導電型摻雜區23的傳輸路徑(Travelling Length)，藉此可降低載子複合的機率，從而增加少數載子進入該第二導電型摻雜區23的機會而增進載子收集效率，並提升該太陽能電池13的光電轉換效率。 In addition, since the number of carriers generated in the portion closer to the front surface 5 in the substrate 2 is higher, and since the substrate 2 of the present embodiment is an n-type semiconductor substrate, the main carrier is an electron, and a minority carrier The sub-hole is a hole, so in the embodiment, the plurality of first holes 51 are disposed above the second conductive type doped region 23, and the plurality of first holes 51 are matched to the back surface 6 so that each The bottom surface 522 of the first surface 52 is also relatively adjacent to the The back surface 6 of the substrate 2 can shorten the distance between the bottom surface 522 of the plurality of first surfaces 52 and the back surface 6 to shorten the transmission path of the minority carrier to the second conductive type doping region 23 (Travelling Length) Thereby, the probability of carrier recombination can be reduced, thereby increasing the chance of a minority carrier entering the second conductivity type doping region 23, improving carrier collection efficiency, and improving the photoelectric conversion efficiency of the solar cell 13.
值得一提的是，由於本實施例還設有該前表面電場區21，該前表面電場區21除了可作為該正面5的鈍化層之外，由於該前表面電場區21的摻雜濃度大於該基板2的摻雜濃度，故該前表面電場區21的導電性優於該基板2，且該前表面電場區21之串聯電阻亦較低而可作為載子移動的通道。進一步地，因為該前表面電場區21沿著該正面5的第一表面52與粗糙面部53配置，不僅可增加該前表面電場區21的接觸面積而增進捕捉載子的機會，該前表面電場區21對應該數個第一表面52的部位也對應地朝該背面6突出。因此，少數載子可進入電阻較低的該前表面電場區21中傳導，並來到該第二導電型摻雜區23上方時，以較短的傳輸路徑進入該第二導電型摻雜區23而被收集。 It is worth mentioning that, since the front surface electric field region 21 is also provided in the embodiment, the front surface electric field region 21 can be used as the passivation layer of the front surface 5, because the doping concentration of the front surface electric field region 21 is greater than The doping concentration of the substrate 2 is such that the front surface electric field region 21 has better conductivity than the substrate 2, and the front surface electric field region 21 has a lower series resistance and can serve as a channel for carrier movement. Further, since the front surface electric field region 21 is disposed along the first surface 52 of the front surface 5 and the rough surface portion 53, the contact area of the front surface electric field region 21 can be increased to increase the chance of capturing the carrier, the front surface electric field. The portion of the region 21 corresponding to the plurality of first surfaces 52 also correspondingly protrudes toward the back surface 6. Therefore, a minority carrier can enter the lower surface electric field region 21 with lower resistance and enter the second conductivity type doping region 23 with a shorter transmission path. 23 was collected.
需要說明的是，為了達成前述效果，在該正面5上每1mm2有500~40000個第一孔洞51。該數個第一孔洞51的孔徑d1為5~40μm，深度d2為5~40μm，較佳地，孔徑d1較小且深度d2較大時，抗反射與提供載子傳導之效果將隨之提昇。 It should be noted that in order to achieve the above effect, there are 500 to 40,000 first holes 51 per 1 mm 2 on the front surface 5. The apertures d1 of the plurality of first holes 51 are 5-40 μm, and the depth d2 is 5-40 μm. Preferably, when the aperture d1 is small and the depth d2 is large, the anti-reflection and the effect of providing carrier conduction are improved. .
當該正面5每1mm2之第一孔洞51的數量小於500時，該正面5的局部區域過於平坦而無法達到降低光反射率之需求；又當該正面5每1mm2之第一孔洞51的數量大於40000時，打孔製程時間過久且缺陷面積較大導致結構強度較弱。 When the number of the first holes 51 per 1 mm 2 of the front surface 5 is less than 500, the partial area of the front surface 5 is too flat to meet the requirement of reducing the light reflectivity; and when the front surface 5 is the first hole 51 per 1 mm 2 When the number is more than 40,000, the punching process time is too long and the defect area is large, resulting in weak structural strength.
當該數個第一孔洞51的孔徑d1小於5μm時，將使得該數個第一孔洞51之底面552的面積變小，而讓載子例如電洞被推送到位於該背面6的該第二導電型摻雜區23(即例如P型摻雜之發射極)的能力變弱；又當該數個第一孔洞51的孔徑d1大於40μm時，會使該正面5的局部區域過於平坦而無法達到降低光反射率之需求。 When the aperture d1 of the plurality of first holes 51 is less than 5 μm, the area of the bottom surface 552 of the plurality of first holes 51 is made smaller, and the carrier such as a hole is pushed to the second portion located on the back surface 6. The ability of the conductive doped region 23 (ie, for example, a P-type doped emitter) is weak; and when the aperture d1 of the plurality of first holes 51 is greater than 40 μm, the local region of the front surface 5 is too flat to be Achieve the need to reduce light reflectivity.
當該數個第一孔洞51的深度d2小於5μm時，每一第一表面52的底面522與該基板2的背面6之距離不夠短，因此鄰近該正面5處所生成的載子之傳輸路徑仍過長，故無法有效降低載子複合的機率；又當該數個第一孔洞51的深度d2大於40μm時，雖然可以縮短載子的傳輸路徑以有效降低載子複合的機率，但因為該數個第一孔洞51過深而降低該基板2整體之結構強度，導致該基板2局部區域的厚度過薄而容易發生應力集中，因而增加該基板2之破片率。 When the depth d2 of the plurality of first holes 51 is less than 5 μm, the distance between the bottom surface 522 of each first surface 52 and the back surface 6 of the substrate 2 is not sufficiently short, so that the transmission path of the carriers generated adjacent to the front surface 5 remains If it is too long, the probability of carrier recombination cannot be effectively reduced. When the depth d2 of the plurality of first holes 51 is greater than 40 μm, although the transmission path of the carrier can be shortened to effectively reduce the probability of carrier recombination, The first holes 51 are too deep to reduce the structural strength of the entire substrate 2, resulting in a thickness of a portion of the substrate 2 being too thin to cause stress concentration, thereby increasing the chipping rate of the substrate 2.
參閱圖8，本發明太陽能電池模組之一第二較佳實施例與該第一較佳實施例大致相同，兩者之間的差別在於：該基板2之正面5的結構。 Referring to FIG. 8, a second preferred embodiment of the solar cell module of the present invention is substantially the same as the first preferred embodiment, and the difference between the two is the structure of the front surface 5 of the substrate 2.
本實施例的基板2的正面5還具有朝該背面6 延伸且縱剖面呈多邊形的數個第二孔洞54與數個第三孔洞56、數個分別圍繞界定出該數個第二孔洞54的第二表面55，以及數個分別圍繞界定出該數個第三孔洞56的第三表面57。所述多邊形由N個邊所構成且N大於3。 The front surface 5 of the substrate 2 of the present embodiment also has a back surface 6 a plurality of second holes 54 extending from the longitudinal section and a plurality of third holes 56, a plurality of second surfaces 55 respectively defining the plurality of second holes 54, and a plurality of respectively defining the plurality of holes The third surface 57 of the third hole 56. The polygon is composed of N sides and N is greater than 3.
該數個第二孔洞54彼此間隔且為二維排列，其位置對應該數個間隔區24，而每一第二表面55具有一平行該背面6的底面552，以及一垂直且圍繞地連接該底面552的側面551。該數個第三孔洞56彼此間隔且為二維排列，其位置對應該數個第一導電型摻雜區22，而每一第三表面57具有一平行該背面6的底面572，以及一垂直且圍繞地連接該底面572的側面571。 The plurality of second holes 54 are spaced apart from each other and arranged in two dimensions, the positions of which correspond to the plurality of spacers 24, and each of the second surfaces 55 has a bottom surface 552 parallel to the back surface 6, and a vertical and surrounding connection Side 551 of bottom surface 552. The plurality of third holes 56 are spaced apart from each other and arranged in two dimensions, the positions of which correspond to the plurality of first conductive type doped regions 22, and each of the third surfaces 57 has a bottom surface 572 parallel to the back surface 6, and a vertical The side surface 571 of the bottom surface 572 is connected around the ground.
於實施上，該數個第二孔洞54及/或該數個第三孔洞56亦可以二維陣列式排列，且彼此間可獨立間隔而無連通。又在本實施例中，每一第二孔洞54與每一第三孔洞56的縱剖面皆呈矩形，並且與該正面5成垂直之型態，但實施上不限於此，只要縱剖面之形狀是由大於3個邊所構成之多邊形即可，該數個第二孔洞54與該數個第三孔洞56各自的縱剖面亦可不相同來作搭配設計。 In practice, the plurality of second holes 54 and/or the plurality of third holes 56 may also be arranged in a two-dimensional array and independently spaced from each other without communication. In this embodiment, each of the second holes 54 and each of the third holes 56 have a rectangular shape and are perpendicular to the front surface 5, but the implementation is not limited thereto, as long as the shape of the longitudinal section is It is only necessary to form a polygon composed of more than three sides, and the longitudinal sections of the plurality of second holes 54 and the plurality of third holes 56 may be different.
該數個第二孔洞54及該數個第三孔洞56之結構皆與該數個第一孔洞51相同，具體而言，該數個第二孔洞54與該數個第三孔洞56的孔徑d1皆為5~40μm，深度d2皆為5~40μm。在該正面5上每1mm2有500~40000個數個第二孔洞54；在該正面5上每1mm2有500~40000個數個第三孔洞56。由於孔徑d1與深度d2之大小，以及該正 面5上每1mm2之孔洞數量的限定意義，與該第一較佳實施例之第一孔洞51的分佈意義相同，不再詳述。 The structures of the plurality of second holes 54 and the plurality of third holes 56 are the same as the plurality of first holes 51. Specifically, the plurality of second holes 54 and the aperture d1 of the plurality of third holes 56 Both are 5~40μm, and the depth d2 is 5~40μm. On the front side 52 with a second number of 500 to 40,000 holes per 54 1mm; 52 on the front side 500 to 40,000 number of third openings 56 per 1mm. Due to the limitation of the size of the aperture d1 and the depth d2 and the number of holes per 1 mm 2 on the front surface 5, the distribution of the first hole 51 of the first preferred embodiment has the same meaning and will not be described in detail.
需要說明的是，本實施例透過該數個第二孔洞54與該數個第三孔洞56的設置，因而可更進一步地降低該正面5整體的光反射效果、提升入光量，並縮短該正面5與該背面6之距離以降低載子複合的機率。當然在實施上，該正面5可僅具有該數個第一孔洞51與該數個第二孔洞54，此外，該正面5也可僅具有該數個第一孔洞51與該數個第三孔洞56，因此該正面5不以同時具有該數個第一孔洞51、該數個第二孔洞54與該數個第三孔洞56三者為必要。 It should be noted that, in this embodiment, the arrangement of the plurality of second holes 54 and the plurality of third holes 56 can further reduce the light reflection effect of the entire front surface 5, increase the amount of light entering, and shorten the front surface. 5 The distance from the back side 6 to reduce the probability of carrier recombination. In practice, the front surface 5 may have only the plurality of first holes 51 and the plurality of second holes 54. In addition, the front surface 5 may have only the plurality of first holes 51 and the plurality of third holes. 56. Therefore, the front surface 5 does not have to have the plurality of first holes 51, the plurality of second holes 54, and the plurality of third holes 56.
參閱圖8、9，本發明太陽能電池13的製造方法之一第二較佳實施例與該第一較佳實施例大致相同，兩者之間的差別在於：在該基板2的正面5使用雷射形成該數個第一孔洞51的過程中，同時也使用雷射在該正面5分別形成朝該背面6延伸且縱剖面呈多邊形的該數個第二孔洞54與該數個第三孔洞56。 Referring to Figures 8 and 9, a second preferred embodiment of the method of fabricating the solar cell 13 of the present invention is substantially the same as the first preferred embodiment. The difference between the two is that the front surface 5 of the substrate 2 is used with a thunder. During the formation of the plurality of first holes 51, the plurality of second holes 54 extending toward the back surface 6 and having a polygonal cross section and the plurality of third holes 56 are respectively formed on the front surface 5 by using a laser. .
接著利用擴散製程分別在該基板2的背面6處之內形成該數個第一導電型摻雜區22與該第二導電型摻雜區23，以及將該數個第一導電型摻雜區22與該第二導電型摻雜區23間隔開來的該數個間隔區24，前述過程中使該第二導電型摻雜區23位置對應該數個第一孔洞51，該數個第一導電型摻雜區22位置對應該數個第三孔洞56，而該數個間隔區24位置對應該數個第二孔洞54。之後便 與該第一較佳實施例之製造方法相同，以形成該太陽能電池13其他的結構。 Then, the plurality of first conductive type doped regions 22 and the second conductive type doped regions 23 are formed in the back surface 6 of the substrate 2 by using a diffusion process, and the plurality of first conductive type doped regions are formed. The plurality of spacers 24 are spaced apart from the second conductive type doping region 23, and the second conductive type doping region 23 is disposed corresponding to the plurality of first holes 51 in the foregoing process, and the plurality of first holes The conductive doped regions 22 are positioned corresponding to a plurality of third holes 56, and the plurality of spacers 24 are positioned corresponding to the plurality of second holes 54. After that The manufacturing method of the first preferred embodiment is the same to form the other structure of the solar cell 13.
參閱圖10，本發明太陽能電池模組之一第三較佳實施例與該第一較佳實施例大致相同，兩者之間的差別在於：該基板2之正面5的結構。 Referring to FIG. 10, a third preferred embodiment of the solar cell module of the present invention is substantially the same as the first preferred embodiment, and the difference between the two is the structure of the front surface 5 of the substrate 2.
本實施例的基板2的正面5具有一朝該背面6延伸且縱剖面呈多邊形的第一孔洞51、一圍繞界定出該第一孔洞51的第一表面52，以及數個分別連接該第一表面52的粗糙面部53。該第一孔洞51位置對應該第二導電型摻雜區23，而該第一表面52具有一與該數個粗糙面部53間隔且鄰近該背面6的底面522，以及一圍繞地連接該底面522的側面521。該底面522具有數個金字塔結構523，該側面521具有數個金字塔結構524，該數個粗糙面部53也具有數個金字塔結構531。 The front surface 5 of the substrate 2 of the present embodiment has a first hole 51 extending toward the back surface 6 and having a polygonal cross section, a first surface 52 surrounding the first hole 51, and a plurality of respectively connecting the first hole The rough surface portion 53 of the surface 52. The first hole 51 corresponds to the second conductive type doped region 23, and the first surface 52 has a bottom surface 522 spaced apart from the plurality of rough portions 53 and adjacent to the back surface 6, and a bottom surface 522 is connected to the bottom surface 522. Side 521. The bottom surface 522 has a plurality of pyramid structures 523 having a plurality of pyramid structures 524, which also have a plurality of pyramid structures 531.
於本實施例中，雖僅於圖10示意出該第二導電型摻雜區23上方僅有單一個的第一孔洞51，但於實施上亦可為複數個第一孔洞51且每一孔洞51皆具有該數個金字塔結構523與該數個金字塔結構524。除此之外，在實施上，該第一表面52亦不以在該側面521形成該數個金字塔結構524為必要。 In the present embodiment, only the first hole 51 having only one single upper portion of the second conductive type doped region 23 is illustrated in FIG. 10, but a plurality of first holes 51 and each hole may be implemented in the embodiment. Each of the 51 has the plurality of pyramid structures 523 and the plurality of pyramid structures 524. In addition, in practice, the first surface 52 is also not necessary to form the plurality of pyramid structures 524 on the side surface 521.
參閱圖10、11，本發明太陽能電池13的製造方法之一第三較佳實施例與該第一較佳實施例大致相同，兩者之間的差別在於：本實施例先在該正面5使用雷射以形成朝該背面6延伸的該第一孔洞51，此時該第一孔洞51 的縱剖面呈矩形。接著對該正面5全部進行粗糙化處理，使該正面5形成連接該第一表面52的該數個粗糙面部53，同時也使該第一表面52的底面522與側面521粗糙化而分別形成該數個金字塔結構523與該數個金字塔結構524。之後便與該第一較佳實施例之製造方法相同，以形成該太陽能電池13其他的結構。 Referring to Figures 10 and 11, a third preferred embodiment of the method for fabricating the solar cell 13 of the present invention is substantially the same as the first preferred embodiment. The difference between the two is that the embodiment is used first on the front surface 5. The laser is formed to form the first hole 51 extending toward the back surface 6, and the first hole 51 is at this time The longitudinal section is rectangular. Then, the front surface 5 is roughened, and the front surface 5 is formed with the plurality of rough surface portions 53 connecting the first surface 52, and the bottom surface 522 and the side surface 521 of the first surface 52 are also roughened to form the surface. A plurality of pyramid structures 523 and the plurality of pyramid structures 524. Thereafter, the manufacturing method of the first preferred embodiment is the same to form the other structure of the solar cell 13.
參閱圖12、13，本發明太陽能電池模組之一第四較佳實施例與該第一較佳實施例大致相同，兩者之間的差別在於：該基板2之正面5的結構。 Referring to Figures 12 and 13, a fourth preferred embodiment of the solar cell module of the present invention is substantially identical to the first preferred embodiment, and the difference between the two is the structure of the front side 5 of the substrate 2.
本實施例的基板2的正面5呈凹凸不平，並還具有數個金字塔結構58。而該數個第一孔洞51分別是由該正面5的金字塔結構58朝該背面6延伸，且該數個第一孔洞51位置對應該第二導電型摻雜區23。在本實施例中，該數個第一孔洞51分別可由該數個金字塔結構58的頂點、稜線，或者相鄰的金字塔結構58的連接處朝該背面6延伸，當然在實施上，該數個第一孔洞51也可僅由該數個金字塔結構58的頂點朝該背面6延伸，或僅由該數個金字塔結構58的稜線朝該背面6延伸，或僅由任兩相鄰的金字塔結構58的連接處朝該背面6延伸，不需特別限制。 The front surface 5 of the substrate 2 of the present embodiment has irregularities and also has a plurality of pyramid structures 58. The plurality of first holes 51 extend from the pyramid structure 58 of the front surface 5 toward the back surface 6, respectively, and the plurality of first holes 51 correspond to the second conductive type doping regions 23. In this embodiment, the plurality of first holes 51 may extend from the vertices of the plurality of pyramid structures 58, ridge lines, or the junctions of the adjacent pyramid structures 58 toward the back surface 6, respectively. Of course, in practice, the plurality of holes The first aperture 51 may also extend only from the apex of the plurality of pyramid structures 58 toward the back surface 6, or only from the ridgelines of the plurality of pyramid structures 58 toward the back surface 6, or only by any two adjacent pyramid structures 58. The connection extends toward the back side 6 without particular limitation.
值得一提的是，在實施上，該正面5當然也還可具有由該正面5的金字塔結構58朝該背面6延伸且縱剖面呈多邊形的數個第二孔洞(圖未示)及/或數個第三孔洞(圖未示)。該數個第二孔洞彼此間隔且位置對應該數個間隔區24，而該數個第三孔洞彼此間隔且位置對應該數個第 一導電型摻雜區22。 It should be noted that, in practice, the front surface 5 may also have a plurality of second holes (not shown) extending from the pyramid structure 58 of the front surface 5 toward the back surface 6 and having a polygonal cross section (not shown) and/or Several third holes (not shown). The plurality of second holes are spaced apart from each other and are positioned corresponding to the plurality of spacers 24, and the plurality of third holes are spaced apart from each other and the positions correspond to the plurality of A conductive type doped region 22.
參閱圖12、13、14，本發明太陽能電池13的製造方法之一第四較佳實施例與該第一較佳實施例大致相同，兩者之間的差別在於：本實施例先在該基板2的正面5全部位置進行粗糙化處理，而使該正面5整面皆形成該數個金字塔結構58，接著於該正面5其中幾個的金字塔結構58上，使用雷射以形成朝該背面6延伸且縱剖面呈多邊形的該數個第一孔洞51。之後便與該第一較佳實施例之製造方法相同，以形成該太陽能電池13其他的結構。 Referring to Figures 12, 13, and 14, a fourth preferred embodiment of the method for fabricating the solar cell 13 of the present invention is substantially the same as the first preferred embodiment. The difference between the two is that the embodiment is preceded by the substrate. The front surface 5 of the second surface 5 is roughened, and the front surface 5 is formed on the entire surface of the front surface 5, and then on the pyramid structure 58 of the front surface 5, a laser is used to form the back surface 6 The plurality of first holes 51 extending and having a polygonal cross section. Thereafter, the manufacturing method of the first preferred embodiment is the same to form the other structure of the solar cell 13.
參閱圖15，本發明太陽能電池模組之一第五較佳實施例與該第三較佳實施例大致相同，該基板2的正面5同樣具有一個朝該背面6延伸且縱剖面呈多邊形的第一孔洞51、一個圍繞界定出該第一孔洞51的第一表面52，以及數個分別連接該第一表面52的粗糙面部53。該第一表面52具有一平行該背面6的底面522，以及一垂直且圍繞地連接該底面522的側面521。 Referring to FIG. 15, a fifth preferred embodiment of the solar cell module of the present invention is substantially the same as the third preferred embodiment. The front surface 5 of the substrate 2 also has a polygonal shape extending toward the back surface 6 and having a polygonal cross section. A hole 51, a first surface 52 surrounding the first hole 51, and a plurality of rough faces 53 respectively connecting the first surface 52. The first surface 52 has a bottom surface 522 that is parallel to the back surface 6, and a side surface 521 that is perpendicularly and circumferentially coupled to the bottom surface 522.
兩者之間的差別在於：本實施例的正面5還具有數個由該第一表面52之底面522朝該背面6延伸且縱剖面呈多邊形的第四孔洞59。在本實施例中，該第一孔洞51與該數個第四孔洞59的縱剖面皆呈矩形。 The difference between the two is that the front surface 5 of the embodiment further has a plurality of fourth holes 59 extending from the bottom surface 522 of the first surface 52 toward the back surface 6 and having a polygonal cross section. In this embodiment, the longitudinal holes of the first hole 51 and the plurality of fourth holes 59 are both rectangular.
參閱圖15、16，本發明太陽能電池13的製造方法之一第五較佳實施例與該第一較佳實施例大致相同，兩者之間的差別在於：本實施例先在該基板2的正面5進行粗糙化處理而使該正面5形成該數個粗糙面部53。接著 於該正面5未形成有該數個粗糙面部53的位置，使用雷射以形成朝該背面6延伸且縱剖面呈多邊形的該第一孔洞51，以及圍繞界定出該第一孔洞51的該第一表面52。最後於該第一表面52之底面522使用雷射以形成朝該背面6延伸且縱剖面呈多邊形的該數個第四孔洞59。之後便與該第一較佳實施例之製造方法相同，以形成該太陽能電池13其他的結構。 Referring to Figures 15 and 16, a fifth preferred embodiment of the method for fabricating the solar cell 13 of the present invention is substantially the same as the first preferred embodiment. The difference between the two is that the present embodiment is first on the substrate 2. The front surface 5 is subjected to roughening treatment so that the front surface 5 forms the plurality of rough surface portions 53. then At a position where the front surface 5 is not formed with the plurality of rough surface portions 53, a laser is used to form the first hole 51 extending toward the back surface 6 and having a polygonal cross section, and the first portion defining the first hole 51 A surface 52. Finally, a laser is used on the bottom surface 522 of the first surface 52 to form the plurality of fourth holes 59 extending toward the back surface 6 and having a polygonal cross section. Thereafter, the manufacturing method of the first preferred embodiment is the same to form the other structure of the solar cell 13.
綜上所述，本發明透過在該正面形成朝該背面延伸的第一孔洞，以及分別圍繞界定出所述第一孔洞的所述第一表面，前述創新的結構設計，除了可降低光反射以進一步地提升入光量與光使用率之外，由於所述第一孔洞是朝該背面延伸，可縮短該正面之第一表面與該背面之間的距離，從而縮短少數載子的傳輸路徑並降低載子複合的機率，因而增加少數載子進入該第二導電型摻雜區的機會而增進載子收集效率，並提升該太陽能電池的光電轉換效率，故確實能達成本發明之目的。 In summary, the present invention provides the foregoing innovative structural design by forming a first hole extending toward the back surface on the front surface and surrounding the first surface defining the first hole, in addition to reducing light reflection. Further, in addition to increasing the amount of light incident and the light usage rate, since the first hole extends toward the back surface, the distance between the first surface of the front surface and the back surface can be shortened, thereby shortening the transmission path of the minority carrier and reducing The probability of carrier recombination, thus increasing the chance of a minority carrier entering the second conductivity type doping region, enhances the carrier collection efficiency, and enhances the photoelectric conversion efficiency of the solar cell, so that the object of the present invention can be achieved.
惟以上所述者，僅為本發明之較佳實施例而已，當不能以此限定本發明實施之範圍，即大凡依本發明申請專利範圍及專利說明書內容所作之簡單的等效變化與修飾，皆仍屬本發明專利涵蓋之範圍內。 The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the patent application scope and patent specification content of the present invention, All remain within the scope of the invention patent.
13‧‧‧太陽能電池 13‧‧‧Solar battery
2‧‧‧基板 2‧‧‧Substrate
21‧‧‧前表面電場區 21‧‧‧ front surface electric field
22‧‧‧第一導電型摻雜區 22‧‧‧First Conductive Doped Area
23‧‧‧第二導電型摻雜區 23‧‧‧Second Conductive Doped Area
24‧‧‧間隔區 24‧‧‧ interval zone
31‧‧‧介電層 31‧‧‧Dielectric layer
32‧‧‧抗反射層 32‧‧‧Anti-reflective layer
41‧‧‧第一電極 41‧‧‧First electrode
42‧‧‧第二電極 42‧‧‧second electrode
5‧‧‧正面 5‧‧‧ positive
51‧‧‧第一孔洞 51‧‧‧First hole
52‧‧‧第一表面 52‧‧‧ first surface
521‧‧‧側面 521‧‧‧ side
522‧‧‧底面 522‧‧‧ bottom
53‧‧‧粗糙面部 53‧‧‧Rough face
531‧‧‧金字塔結構 531‧‧‧ Pyramid structure
6‧‧‧背面 6‧‧‧ Back
d1‧‧‧孔徑 D1‧‧‧ aperture
d2‧‧‧深度 D2‧‧ depth
d3‧‧‧高度 D3‧‧‧ Height
d4‧‧‧間距 D4‧‧‧ spacing
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