TWM551757U

TWM551757U - Solar absorption layer

Info

Publication number: TWM551757U
Application number: TW106206255U
Authority: TW
Inventors: 吳世雄; 黃冠達; 施權峰
Original assignee: 施權峰; 吳世雄; 榮佑科技股份有限公司
Priority date: 2017-05-04
Filing date: 2017-05-04
Publication date: 2017-11-11

Abstract

Disclosed is a solar absorption layer. The solar absorption layer includes: a back electrode; a first absorption layer being disposed on the back electrode; and a second absorption layer being disposed on the first absorption layer, wherein a ratio of sulfur content to selenium content for the first absorption layer is different from that for the second absorption layer.

Description

太陽能吸收層Solar absorption layer

本創作係一種太陽能吸收層，特別是有關於一種銅鋅錫硫硒(CZTSSe)太陽能吸收層。The present invention is a solar energy absorbing layer, in particular, a copper zinc tin sulphide selenide (CZTSSe) solar absorbing layer.

地球上的能源日漸減少，但是人類對於能源的依賴卻是日益增加，尋找替代能源成為人類的重要課題。在所有替代能源中，太陽能取之不竭用之不盡，且不像其他火力發電或核能發電會造成環境汙染，因此能將太陽能轉變為電能的太陽能電池被視為解決能源問題的重要技術。The energy on Earth is decreasing, but human dependence on energy is increasing. Finding alternative energy sources has become an important issue for human beings. In all alternative energy sources, solar energy is inexhaustible, and unlike other thermal or nuclear power generation, which causes environmental pollution, solar cells that convert solar energy into electrical energy are regarded as important technologies for solving energy problems.

在各種下世代半導體太陽能電池裡，I-III-VI族硒化銅銦鎵(CIGSe)是目前最有潛力的無機薄膜太陽能材料，最高轉換效率已經達到19.9%，且已有適合低成本與卷對卷(roll-to-roll)大量生產的技術。然而隨著半導體工業蓬勃發展，ITO被廣泛使用於電子元件的透明導電層，導致稀有金屬銦(In)的需求量及價格日益增加，造成不利於大面積CIGSe太陽能電池製作，因此找尋具有儲量大、低單價的替代性材料來取代CIGSe以製作更高效率且低成本的太陽能電池，成為新世代太陽能電池的研究議題。Among the next generation of semiconductor solar cells, I-III-VI selenium-copper indium gallium (CIGSe) is currently the most promising inorganic thin-film solar material, with a maximum conversion efficiency of 19.9%, and is suitable for low cost and volume. A technique for mass production of roll-to-roll. However, with the booming of the semiconductor industry, ITO is widely used in the transparent conductive layer of electronic components, resulting in the increasing demand and price of rare metal indium (In), which is not conducive to the production of large-area CIGSe solar cells, so it has a large reserve. Low-cost alternative materials to replace CIGSe to produce more efficient and low-cost solar cells have become the research topic of new generation solar cells.

近年來有許多研究硒化銅鋅錫(CZTSe)和硫化銅鋅錫(CZTS)等I-II-IV-VI族四元化合物半導體材料，其具備直接能隙1.0~1.5 eV、光吸收係數10 ⁴cm ^-1，且組成元素鋅和錫為豐富便宜且無毒性特性，是適合取代CIGSe的選擇。 In recent years, there have been many studies on I-II-IV-VI quaternary compound semiconductor materials such as copper selenide (CZTSe) and copper zinc tin (CZTS), which have a direct energy gap of 1.0 to 1.5 eV and a light absorption coefficient of 10 ⁴ cm ^-1 , and the constituent elements zinc and tin are rich and cheap and non-toxic, and are suitable for replacing CIGSe.

如圖1所示，圖1係繪示習知CZTSe太陽能吸收層結構之剖面示意圖。習知CZTSe太陽能吸收層包含背電極11及單一吸收層12。習知製作CZTSe太陽能吸收層12的方法可分為真空與非真空製程，真空製程方法主要有蒸鍍和濺鍍兩種，非真空製程技術主要有溶液溶膠法和奈米粒子合成。然而，不論真空或非真空製程，均是先沉積吸收層前驅物，然後再進行硒化熱處理形成吸收層12。且習知CZTSe太陽能吸收層的能隙為1.0 eV，雖可以吸收大部分波長的光並轉換為電能，得到高的短路電流，但因為吸收層窄能隙原因，造成低的開路電壓。As shown in FIG. 1, FIG. 1 is a schematic cross-sectional view showing the structure of a conventional CZTSe solar absorption layer. The conventional CZTSe solar absorbing layer comprises a back electrode 11 and a single absorbing layer 12. Conventionally, the method for fabricating the CZTSe solar energy absorbing layer 12 can be divided into vacuum and non-vacuum processes. The vacuum process methods mainly include evaporation and sputtering. The non-vacuum process technology mainly includes solution sol method and nano particle synthesis. However, regardless of the vacuum or non-vacuum process, the absorber layer precursor is deposited first, and then subjected to a selenization heat treatment to form the absorber layer 12. Moreover, the CZTSe solar absorption layer has an energy gap of 1.0 eV. Although it can absorb most of the wavelength light and convert it into electric energy, it obtains a high short-circuit current, but causes a low open circuit voltage due to the narrow energy gap of the absorption layer.

有鑑於上述習知技藝之問題，本創作之目的在於提供一種銅鋅錫硫硒(CZTSSe)太陽能吸收層，以藉由增加吸收層表面的能隙來提高太陽能電池的開路電壓。In view of the above-mentioned problems of the prior art, the purpose of the present invention is to provide a copper zinc tin sulphide selenide (CZTSSe) solar absorbing layer to increase the open circuit voltage of the solar cell by increasing the energy gap of the surface of the absorbing layer.

為達前述目的，本創作提供一種太陽能吸收層，包含：背電極；第一吸收層，係設置於背電極上；以及第二吸收層，係設置於第一吸收層上；其中，第一吸收層之硫含量與硒含量之比例係相異於第二吸收層之硫含量與硒含量之比例。To achieve the foregoing objective, the present invention provides a solar energy absorbing layer comprising: a back electrode; a first absorbing layer disposed on the back electrode; and a second absorbing layer disposed on the first absorbing layer; wherein the first absorption The ratio of the sulfur content of the layer to the selenium content is different from the ratio of the sulfur content of the second absorption layer to the selenium content.

前述之第二吸收層之硫含量高於第二吸收層之硒含量。The aforementioned second absorption layer has a higher sulfur content than the second absorption layer.

前述之第二吸收層之硫含量佔第二吸收層之硫硒總含量的40~100%。The sulfur content of the second absorption layer is 40% to 100% of the total sulfur and selenium content of the second absorption layer.

前述之第一吸收層之硒含量高於第一吸收層之硫含量。The selenium content of the first absorption layer is higher than the sulfur content of the first absorption layer.

前述之第一吸收層之硫含量佔第一吸收層之硫硒總含量的0~15%。The sulfur content of the first absorption layer is from 0 to 15% of the total content of sulfur and selenium in the first absorption layer.

綜上所述，本創作之太陽能吸收層藉由控制第一吸收層及第二吸收層之硫含量與硒含量之比例來提高太陽能電池的開路電壓。In summary, the solar absorption layer of the present invention increases the open circuit voltage of the solar cell by controlling the ratio of the sulfur content of the first absorption layer and the second absorption layer to the selenium content.

為利貴審查員瞭解本創作之技術特徵、內容與優點及其所能達成之功效，茲將本創作配合圖式，並以實施例之表達形式詳細說明如下，而其中所使用之圖式，其主旨僅為示意及輔助說明書之用，未必為本創作實施後之真實比例與精準配置，故不應就所附之圖式的比例與配置關係解讀、侷限本創作於實際實施上的權利範圍，合先敘明。In order to understand the technical characteristics, content and advantages of the creation and the effects that can be achieved by the examiner, the author will cooperate with the schema and explain the following in the form of the embodiment, and the schema used therein The subject matter is only for the purpose of illustration and supplementary instructions. It is not necessarily the true proportion and precise configuration after the implementation of the original creation. Therefore, the proportions and configuration relationships of the attached drawings should not be interpreted or limited in the actual implementation scope. First described.

請參閱圖2至圖5，圖2至圖5係繪示本創作之太陽能吸收層之較佳實施例之製作流程之剖面示意圖。Please refer to FIG. 2 to FIG. 5 . FIG. 2 to FIG. 5 are schematic cross-sectional views showing a manufacturing process of a preferred embodiment of the solar energy absorbing layer of the present invention.

如圖2所示，提供背電極21，其中背電極之材料為鉬(Mo)金屬。As shown in FIG. 2, a back electrode 21 is provided, wherein the material of the back electrode is molybdenum (Mo) metal.

接著，如圖3所示，在背電極21上沉積前驅物22，其中前驅物22可例如為硫化銅鋅錫(CZTS)前驅物。本創作之較佳實施例係使用非真空化學溶液塗佈方式(如旋轉塗佈法)將前驅物22沉積於背電極21上。Next, as shown in FIG. 3, a precursor 22 is deposited on the back electrode 21, wherein the precursor 22 can be, for example, a copper zinc tin sulfide (CZTS) precursor. The preferred embodiment of the present invention deposits the precursor 22 on the back electrode 21 using a non-vacuum chemical solution coating method such as spin coating.

接著，如圖4所示，將前驅物22連同背電極21進行硒化熱處理，以令前驅物22全部或部分反應形成第一吸收層23，其中第一吸收層23可例如為硒化銅鋅錫(CZTSe)吸收層。Next, as shown in FIG. 4, the precursor 22 is subjected to a selenization heat treatment together with the back electrode 21 to cause the precursor 22 to react wholly or partially to form the first absorption layer 23, wherein the first absorption layer 23 may be, for example, copper zinc zinc selenide. Tin (CZTSe) absorber layer.

本創作之較佳實施例所使用的硒化熱處理步驟大致如下：將前驅物22連同背電極21置入爐管中，並將爐管抽至真空。接著將爐管加熱至400~600 ^oC，持溫10分鐘至4小時。由於爐管內含有硒(Se)粉或通入硒化氫(H ₂Se)氣體，因此在高溫環境下，前驅物22會與硒反應而全部或部分形成第一吸收層23。 The selenization heat treatment step used in the preferred embodiment of the present invention is substantially as follows: The precursor 22 is placed in the furnace tube along with the back electrode 21, and the furnace tube is evacuated to a vacuum. The tube is then heated to 400-600 ^o C for 10 minutes to 4 hours. Since the furnace tube contains selenium (Se) powder or a hydrogen selenide (H ₂ Se) gas, the precursor 22 reacts with selenium to form the first absorption layer 23 in whole or in part in a high temperature environment.

接著，如圖5所示，將吸收層23連同背電極21進行硫化熱處理，以令部分表面的第一吸收層23反應形成第二吸收層24，其中第二吸收層24可例如為銅鋅錫硫硒(CZTSSe)吸收層。其中，第二吸收層24之硫含量高於第二吸收層24之硒含量，且第二吸收層24之硫含量佔第二吸收層24之VI族元素含量(例如硫硒總含量)的40~100%；以及第一吸收層23之硒含量高於第一吸收層23之硫含量，且第一吸收層23之硫含量佔第一吸收層23之VI族元素含量(例如硫硒總含量)的0~15%。Next, as shown in FIG. 5, the absorbing layer 23 is subjected to a vulcanization heat treatment together with the back electrode 21 to react the first absorbing layer 23 of the partial surface to form the second absorbing layer 24, wherein the second absorbing layer 24 may be, for example, copper zinc tin. Sulfur and selenium (CZTSSe) absorber layer. Wherein, the sulfur content of the second absorption layer 24 is higher than the selenium content of the second absorption layer 24, and the sulfur content of the second absorption layer 24 accounts for 40% of the content of the VI group element of the second absorption layer 24 (for example, the total content of sulfur and selenium). ~100%; and the selenium content of the first absorption layer 23 is higher than the sulfur content of the first absorption layer 23, and the sulfur content of the first absorption layer 23 accounts for the content of the group VI element of the first absorption layer 23 (for example, the total content of sulfur and selenium) ) 0~15%.

本創作之較佳實施例所使用的硫化熱處理步驟大致如下：將第一吸收層23連同背電極21置入爐管中，並將爐管抽至真空。接著將爐管加熱至400~600 ^oC，持溫10分鐘至4小時。由於爐管內有硫(S)粉或通入硫化氫(H ₂S)氣體，因此在高溫環境下，部分表面的第一吸收層23會與硫反應而形成第二吸收層24。 The vulcanization heat treatment step used in the preferred embodiment of the present invention is substantially as follows: the first absorbent layer 23 is placed in the furnace tube together with the back electrode 21, and the furnace tube is evacuated to a vacuum. The tube is then heated to 400-600 ^o C for 10 minutes to 4 hours. Since the furnace tube has sulfur (S) powder or hydrogen sulfide (H ₂ S) gas, the first absorption layer 23 on a part of the surface reacts with sulfur to form the second absorption layer 24 in a high temperature environment.

請接續參閱圖6，圖6係繪示本創作之太陽能吸收層之較佳實施例之元素分布圖。此元素分布圖係使用二次離子質譜分析(Secondary Ion Mass Spectrometry，SIMS)，其縱軸為元素含量，橫軸為深度。從元素分布圖可以確認，本創作之太陽能吸收層在表面250 nm的硫元素含量較高(即第二吸收層24之硫含量高於硒含量)。Please refer to FIG. 6. FIG. 6 is a diagram showing the element distribution of the preferred embodiment of the solar absorbing layer of the present invention. This elemental distribution map uses Secondary Ion Mass Spectrometry (SIMS) with the vertical axis as the elemental content and the horizontal axis as the depth. It can be confirmed from the elemental distribution map that the solar absorption layer of the present invention has a high sulfur element content at a surface of 250 nm (i.e., the sulfur content of the second absorption layer 24 is higher than that of the selenium content).

請接續參閱圖7，圖7係繪示本創作之太陽能吸收層之較佳實施例之太陽能電池效率圖。從太陽能電池效率圖(I-V曲線圖)可以確認，利用本創作之太陽能吸收層所製作出的CZTSSe太陽能電池，其開路電壓大於習知的CZTSe太陽能電池。Please refer to FIG. 7, which is a solar cell efficiency diagram of a preferred embodiment of the solar absorbing layer of the present invention. From the solar cell efficiency map (I-V graph), it was confirmed that the CZTSSe solar cell fabricated by the solar absorbing layer of the present invention has an open circuit voltage higher than that of the conventional CZTSe solar cell.

上述所揭露的各個實施例僅為例示性，而非為限制性。任何未背離本創作的精神與範疇，而對本創作的所揭露的實施例進行的等效修改或變更，皆應包含於後附的申請專利範圍中。The various embodiments disclosed above are illustrative only and not limiting. Any equivalent modifications or alterations to the disclosed embodiments of the present invention are intended to be included within the scope of the appended claims.

11‧‧‧背電極
12‧‧‧吸收層
21‧‧‧背電極
22‧‧‧前驅物
23‧‧‧第一吸收層
24‧‧‧第二吸收層11‧‧‧Back electrode
12‧‧‧absorbing layer
21‧‧‧ Back electrode
22‧‧‧Precursors
23‧‧‧First absorption layer
24‧‧‧Second absorption layer

圖1係繪示習知CZTSe太陽能吸收層結構之剖面示意圖。FIG. 1 is a schematic cross-sectional view showing the structure of a conventional CZTSe solar energy absorbing layer.

圖2至圖5係繪示本創作之太陽能吸收層之較佳實施例之製作流程之剖面示意圖。2 to 5 are schematic cross-sectional views showing a manufacturing process of a preferred embodiment of the solar absorbing layer of the present invention.

圖6係繪示本創作之太陽能吸收層之較佳實施例之元素分布圖。Figure 6 is a diagram showing the element distribution of a preferred embodiment of the solar absorbing layer of the present invention.

圖7係繪示本創作之太陽能吸收層之較佳實施例之太陽能電池效率圖。Figure 7 is a graph showing the solar cell efficiency of a preferred embodiment of the solar absorbing layer of the present invention.

21‧‧‧背電極 21‧‧‧ Back electrode

23‧‧‧第一吸收層 23‧‧‧First absorption layer

24‧‧‧第二吸收層 24‧‧‧Second absorption layer

Claims

一種太陽能吸收層，包含：一背電極；一第一吸收層，係設置於該背電極上；以及一第二吸收層，係設置於該第一吸收層上；其中，該第一吸收層之硫含量與硒含量之比例係相異於該第二吸收層之硫含量與硒含量之比例。A solar energy absorbing layer comprising: a back electrode; a first absorbing layer disposed on the back electrode; and a second absorbing layer disposed on the first absorbing layer; wherein the first absorbing layer The ratio of sulfur content to selenium content is different from the ratio of sulfur content to selenium content of the second absorption layer.

如申請專利範圍第1項所述之太陽能吸收層，其中該第二吸收層之硫含量高於該第二吸收層之硒含量。The solar energy absorbing layer according to claim 1, wherein the second absorbing layer has a higher sulfur content than the second absorbing layer.

如申請專利範圍第2項所述之太陽能吸收層，其中該第二吸收層之硫含量佔該第二吸收層之硫硒總含量的40~100%。The solar energy absorbing layer according to claim 2, wherein the second absorbing layer has a sulfur content of 40 to 100% of the total sulphur and selenium content of the second absorbing layer.

如申請專利範圍第1項所述之太陽能吸收層，其中該第一吸收層之硒含量高於該第一吸收層之硫含量。The solar energy absorbing layer according to claim 1, wherein the first absorbing layer has a selenium content higher than a sulphur content of the first absorbing layer.

如申請專利範圍第4項所述之太陽能吸收層，其中該第一吸收層之硫含量佔該第一吸收層之硫硒總含量的0~15%。The solar energy absorbing layer according to claim 4, wherein the first absorbing layer has a sulfur content of 0 to 15% of the total sulphur and selenium content of the first absorbing layer.