CN117479808A - MIM absorber-based long-wave infrared thermoelectric detector and preparation method thereof - Google Patents
MIM absorber-based long-wave infrared thermoelectric detector and preparation method thereof Download PDFInfo
- Publication number
- CN117479808A CN117479808A CN202210841060.0A CN202210841060A CN117479808A CN 117479808 A CN117479808 A CN 117479808A CN 202210841060 A CN202210841060 A CN 202210841060A CN 117479808 A CN117479808 A CN 117479808A
- Authority
- CN
- China
- Prior art keywords
- layer
- metal
- mim
- absorber
- thermoelectric conversion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000006096 absorbing agent Substances 0.000 title claims abstract description 71
- 238000002360 preparation method Methods 0.000 title abstract description 15
- 229910052751 metal Inorganic materials 0.000 claims abstract description 144
- 239000002184 metal Substances 0.000 claims abstract description 144
- 238000006243 chemical reaction Methods 0.000 claims abstract description 62
- 239000000463 material Substances 0.000 claims abstract description 38
- 238000000034 method Methods 0.000 claims abstract description 17
- 229910052782 aluminium Inorganic materials 0.000 claims description 53
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 47
- 229910052732 germanium Inorganic materials 0.000 claims description 20
- 238000003491 array Methods 0.000 claims description 16
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 15
- 229910052804 chromium Inorganic materials 0.000 claims description 15
- 239000011651 chromium Substances 0.000 claims description 15
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 claims description 14
- 238000004519 manufacturing process Methods 0.000 claims description 10
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 6
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 3
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 3
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 3
- 229910052802 copper Inorganic materials 0.000 claims description 3
- 239000010949 copper Substances 0.000 claims description 3
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 3
- 229910052737 gold Inorganic materials 0.000 claims description 3
- 239000010931 gold Substances 0.000 claims description 3
- 229910052759 nickel Inorganic materials 0.000 claims description 3
- 229910052697 platinum Inorganic materials 0.000 claims description 3
- 229910052709 silver Inorganic materials 0.000 claims description 3
- 239000004332 silver Substances 0.000 claims description 3
- 229910052719 titanium Inorganic materials 0.000 claims description 3
- 239000010936 titanium Substances 0.000 claims description 3
- 238000010521 absorption reaction Methods 0.000 abstract description 18
- 230000004044 response Effects 0.000 abstract description 11
- 230000008569 process Effects 0.000 abstract description 5
- 230000001105 regulatory effect Effects 0.000 abstract 1
- 238000001514 detection method Methods 0.000 description 7
- 229920002120 photoresistant polymer Polymers 0.000 description 7
- 238000000151 deposition Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910002367 SrTiO Inorganic materials 0.000 description 2
- 238000000862 absorption spectrum Methods 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 239000002041 carbon nanotube Substances 0.000 description 2
- 229910021393 carbon nanotube Inorganic materials 0.000 description 2
- 238000005566 electron beam evaporation Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 238000002207 thermal evaporation Methods 0.000 description 2
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 1
- 229910000530 Gallium indium arsenide Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000002800 charge carrier Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007123 defense Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000004297 night vision Effects 0.000 description 1
- 230000005693 optoelectronics Effects 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
Landscapes
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Abstract
The invention provides a long-wave infrared thermoelectric detector based on MIM absorber and its preparation method, the detector includes: a thermoelectric conversion layer; an upper electrode and a lower electrode respectively arranged on the upper surface and the lower surface of the thermoelectric conversion layer; the MIM absorber is arranged on the surface of the upper electrode and is used for absorbing photons and converting the photons into heat energy, and the MIM absorber sequentially comprises a metal reflecting layer, a dielectric layer and a metal array layer, wherein the metal reflecting layer is arranged on the surface of the upper electrode. According to the invention, 100% perfect absorption of photons is realized by means of the MIM absorber, and the absorbed photons are limited on the upper surface of the thermoelectric conversion layer by utilizing the metal reflection layer, so that the temperature difference is generated on the upper surface and the lower surface of the thermoelectric conversion layer, the channel length between two electrodes is reduced, and the response time is shortened; the absorption bandwidth and the absorption peak wavelength are regulated and controlled by the size and the array period of the metal modules in the metal array layer; the material of the invention has low cost and simple process, can realize large-area preparation and is easy to popularize.
Description
Technical Field
The invention relates to the field of photoelectron information, in particular to a long-wave infrared thermoelectric detector based on an MIM absorber and a preparation method thereof.
Background
In the field of optoelectronic information, the utilization of optical information is one of the most important components, while a photoelectric detector is the basis of utilizing the photoelectric information, and the photoelectric detector is a device for converting optical signals into electric signals and outputting the electric signals, and has very wide application in the fields of national defense, military and civil use. In addition, photo-thermal detectors are also increasingly known, and the photo-thermal detectors are passive devices based on two physical processes of photo-thermal conversion and thermoelectric conversion, and can realize long-wave infrared and terahertz room temperature detection. The traditional photo-thermal electric detector utilizes the heat absorption layer to absorb light to generate heat, and then temperature difference is generated at two sides of the thermopile to generate voltage so as to realize photo-detection, but the preparation process of the device is complex, the price is high, the corresponding sensitivity is low, and the application scene is very limited.
The wavelength range of the long-wave infrared is 8 μm to 14 μm, the absorption of the atmosphere to light in the long-wave infrared is relatively weak, and the radiation emitted from the room-temperature object is mainly in this region, the peak wavelength is about 10 μm, so that the long-wave infrared photodetector is very important for thermal search technologies such as all-weather monitoring and night vision. For detecting low energy radiation, such as long wave infrared, by a photon detector, the photosensitive material typically used is a narrow bandgap semiconductor, e.g., hgCdTe; quantum wells, such as GaAs/InGaAs. For these photodetectors, dark current at room temperature is usually large, so a cryocooling unit is necessary, which undoubtedly increases the size and weight of the photodetector, and thus is crucial for development of uncooled long-wave infrared photodetectors, while the use of thermoelectric detection can effectively solve the problem that the photodetectors need cryocooling.
As high performance thermoelectric materials that can operate at room temperature continue to be discovered, photo-photodetectors are rapidly evolving. Although the photoelectric detector can work at room temperature, compared with a photoelectric detector, the traditional photoelectric detector has the advantages that phonon is used for leading transmission, the response time is relatively long, usually about millisecond, besides developing a novel high-performance thermoelectric material, the high light absorptivity and the responsivity of the photoelectric detector are enhanced by introducing micro-nano optical means such as surface plasmons, phonon absorption and the like, the size of the photoelectric detector is reduced, and the response time is shortened, so that the photoelectric detector becomes a method for realizing ultra-fast long-wave infrared photoelectric detection.
In view of the above, it is necessary to provide a long-wave infrared thermoelectric detector based on MIM absorber and a method for manufacturing the same, which are used for solving the problems of long corresponding time, large size, small light absorptivity, complex manufacturing process and high price of the thermoelectric detector in the prior art.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, the present invention aims to provide a long-wave infrared thermoelectric detector based on an MIM absorber and a method for manufacturing the same, which are used for solving the problems of long corresponding time, large size, small light absorptivity, complex manufacturing process and high price of the thermoelectric detector in the prior art.
To achieve the above and other related objects, the present invention provides a MIM absorber-based long wave infrared pyroelectric detector comprising:
a thermoelectric conversion layer for thermoelectric conversion;
an upper electrode and a lower electrode respectively arranged on the upper surface and the lower surface of the thermoelectric conversion layer;
the MIM absorber is arranged on the surface of the upper electrode and is used for absorbing photons and converting the photons into heat energy, and the area of the MIM absorber is smaller than that of the thermoelectric conversion layer;
the MIM absorber sequentially comprises a metal reflecting layer, a dielectric layer and a metal array layer, wherein the metal reflecting layer is arranged on the surface of the upper electrode, the metal reflecting layer is made of the same material as the metal array layer, the metal array layer is formed by periodically arranging a plurality of regular metal modules in a central symmetry mode, and the radius range of a circumscribed circle of the cross section of each metal module is 0.5-0.7 mu m; the array period of the metal array layer ranges from 1.5 mu m to 2.5 mu m.
Optionally, the number of arrays in the metal array layer is greater than or equal to 1; when the number of arrays in the metal array layer is 1, the radius of the circumscribed circle of the cross section of the metal module is completely the same, and the metal module is used for absorbing infrared rays with single wavelength; when the number of the arrays in the metal array layer is more than 1, the radii of the circumscribed circles of the cross sections of the metal modules of different arrays are different and are used for absorbing infrared rays with different wavelengths.
Optionally, the metal reflective layer and the metal array layer in the MIM absorber are made of one or a combination of more than two of aluminum, gold, silver and copper.
Optionally, the cross section of the metal module of the metal array layer is one or a combination of more than two of a circle, a square and a regular hexagon.
Optionally, the metal reflective layer and the metal array layer in the MIM absorber are made of aluminum, and the dielectric layer is made of germanium, wherein the cross section of the metal module in the metal array layer is circular, so that the MIM absorber layer of the aluminum reflective layer-germanium layer-aluminum disk array layer structure is formed.
Optionally, the thickness of the aluminum disc array layer ranges from 40nm to 60nm, the thickness of the germanium layer ranges from 120nm to 180nm, and the thickness of the aluminum reflecting layer ranges from 120nm to 180nm.
Optionally, the materials of the upper electrode and the lower electrode are the same, and the materials of the upper electrode and the lower electrode are one of chromium, platinum, nickel and titanium.
Optionally, the upper electrode and the lower electrode are in ohmic contact with the thermoelectric conversion layer.
Optionally, the seebeck coefficient of the thermoelectric conversion layer material ranges > 50uV/K.
The invention also provides a preparation method of the long-wave infrared thermoelectric detector based on the MIM absorber, which is used for preparing the long-wave infrared thermoelectric detector based on the MIM absorber, and comprises the following steps:
s1: providing a thermoelectric conversion layer;
s2: forming an upper electrode and a lower electrode on the upper surface and the lower surface of the thermoelectric conversion layer respectively;
s3: forming a metal reflecting layer on the surface of the upper electrode;
s4: forming a dielectric layer on the surface of the metal reflecting layer;
s5: and forming a metal array layer on the surface of the dielectric layer.
As described above, the long-wave infrared thermoelectric detector based on the MIM absorber and the preparation method thereof have the following beneficial effects: according to the invention, 100% perfect absorption of photons is realized by means of the MIM absorber, and the absorbed photons are limited on the upper surface of the thermoelectric conversion layer by utilizing the metal reflection layer, so that the temperature difference is generated on the upper surface and the lower surface of the thermoelectric conversion layer, the channel length between two electrodes is reduced, and the response time is shortened; the invention regulates and controls the absorption bandwidth and the absorption peak wavelength by the size of the metal module in the metal array layer and the array period; in addition, the material of the invention has low cost and simple preparation process, can realize large-area preparation and is easy to popularize.
Drawings
Fig. 1 shows a schematic diagram of a long-wave infrared thermoelectric detector based on an MIM absorber according to the present invention.
Fig. 2 shows a schematic cross-sectional view of a MIM absorber according to the present invention.
Fig. 3 shows the absorption spectrum of an MIM absorber having an aluminum reflective layer-germanium layer-aluminum disk array layer structure in which the array period of the aluminum disk array layer is 2 μm in an embodiment of the present invention.
Fig. 4 shows a schematic flow chart of a method for manufacturing a long-wave infrared thermoelectric detector based on an MIM absorber according to the present invention.
Fig. 5 to 13 show schematic structural views of steps of a method for manufacturing a MIM absorber-based long-wave infrared pyroelectric detector according to the present invention.
Description of element reference numerals
10. Thermoelectric conversion layer
20. Lower electrode
30. Upper electrode
40. Metal reflective layer
50. Dielectric layer
60. Photoresist layer
61. Pattern mask layer
70. Metal array layer
Detailed Description
Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention.
Please refer to fig. 1 to 13. It should be noted that, the illustrations provided in the present embodiment merely illustrate the basic concept of the present invention by way of illustration, and only the components related to the present invention are shown in the drawings rather than the number, shape and size of the components in actual implementation, and the form, number and proportion of each component in actual implementation may be arbitrarily changed, and the layout of the components may be more complex.
Example 1
As shown in fig. 1 to 2, the present embodiment provides a MIM absorber-based long-wave infrared pyroelectric detector, which includes:
a thermoelectric conversion layer 10 for thermoelectric conversion;
upper electrode 30 and lower electrode 20 respectively provided on upper and lower surfaces of thermoelectric conversion layer 10;
a MIM absorber provided on the surface of the upper electrode 30 for absorbing photons and converting them into heat energy, the MIM absorber having an area smaller than the area of the thermoelectric conversion layer 10 (as shown in fig. 1);
the MIM absorber sequentially comprises a metal reflecting layer 40, a dielectric layer 50 and a metal array layer 70, wherein the metal reflecting layer 40 is arranged on the surface of the upper electrode 30, the metal reflecting layer 40 and the metal array layer 70 are made of the same material, the metal array layer 70 is formed by periodically arranging a plurality of regular metal modules in a central symmetry mode, and the radius range of a circumscribed circle of the cross section of each metal module is 0.5-0.7 μm; the array period of the metal array layer 70 ranges from 1.5 μm to 2.5 μm.
It should be noted that, the area of the metal array layer 70 needs to be larger than the area of the incident light spot, so as to be able to effectively absorb photons in the incident light spot; the MIM absorber is a sandwich structure of a Metal reflective layer 40-a dielectric layer 50-a Metal array layer 70 in sequence, wherein MIM is an abbreviation of Metal-Insulator-Metal, the area of the MIM absorber is smaller than the area of the thermoelectric conversion layer 10, and the remaining part is used for exposing the upper electrode 30, while the lower electrode 20 is symmetrically arranged with the upper electrode 30 under the hot spot conversion layer 10; the method comprises the steps of carrying out a first treatment on the surface of the The array period of the metal array layer 70 is the distance between the centers of two adjacent metal modules.
The working principle of the embodiment is as follows: by providing a MIM absorber of a sandwich structure of a metal reflective layer 40-dielectric layer 50-metal array layer 70 on the upper surface of the device, incident light is incident from the upper surface of the MIM absorber, 100% perfect absorption of photons in the incident light is achieved, the absorbed light energy is converted into heat energy inside the MIM absorber due to energy conversion, and the heat energy is localized inside the MIM absorber by the metal reflective layer 40, so that a temperature difference is generated on the upper and lower surfaces of the thermoelectric conversion layer 10, the temperature difference drives directional diffusion of charge carriers from the hot end to the cold end, thereby creating a potential difference, reducing the channel length between the lower electrode 20 and the upper electrode 30, thereby reducing response time, and completing thermoelectric conversion in the thermoelectric conversion layer 10.
In this embodiment, 100% perfect absorption of photons is achieved by using the MIM absorber, and the absorbed photons are localized on the upper surface of the thermoelectric conversion layer 10 by using the metal reflective layer 40, so that a temperature difference is generated between the upper surface and the lower surface of the thermoelectric conversion layer 10, and the channel length between the two electrodes is reduced, thereby reducing the response time; in this embodiment, the absorption bandwidth and the absorption peak wavelength are controlled by the size of the metal modules in the metal array layer 70 and the array period. In addition, the material of the embodiment has low cost and simple preparation process, can realize large-area preparation and is easy to popularize.
As an example, the number of arrays in the metal array layer 70 is 1 or more; when the number of arrays in the metal array layer 70 is 1, the radius of the circumscribed circle of the cross section of the metal module is completely the same, so as to absorb infrared rays with a single wavelength; when the number of arrays in the metal array layer 70 is greater than 1, the radii of the circles circumscribing the cross sections of the metal modules of different arrays are different, so as to absorb infrared rays with different wavelengths. It should be noted that, the radius of the circumcircle of the cross section of the metal module needs to be in the range of 0.5 μm to 0.7 μm to ensure the absorption of the long-wave infrared.
The area of the metal array layer 70 on the MIM absorber-based long-wave infrared pyroelectric detector needs to be larger than the area of the incident light spot to be able to effectively absorb photons in the incident light spot. When only one array is in the metal array layer 70, the radius of the circumscribed circle of the cross section of all the metal modules is completely consistent, and only infrared rays with a single wavelength can be absorbed; the long-wave infrared thermoelectric detector based on the MIM absorber may further absorb infrared rays with different wavelengths, at this time, the metal array layer 70 includes at least two arrays, which are combinations of different regular array areas, the radii of the circles circumscribed by the cross sections of the metal modules in the different array areas are different, and the different radii and the sizes are correspondingly used for absorbing infrared rays with different wavelengths, so as to increase the detection wavelength range of the detector. The above two cases can realize the multi-functional detection of the present embodiment.
It should be noted that, when the MIM absorber-based long-wave infrared thermoelectric detector is used as a detector for absorbing infrared light with different wavelengths, the metal array layer 70 may be formed by not only dividing the metal array layer 70 into different regular array regions, but also staggering the metal modules with different radius dimensions, but in view of the manufacturing process and overall performance, most of the manufacturing processes are regular array regions.
As an example, the materials of the metal reflective layer 40 and the metal array layer 70 in the MIM absorber are one or a combination of two or more of aluminum, gold, silver, and copper.
The materials of the metal reflective layer 40 and the metal array layer 70 include, but are not limited to, the above materials, as long as the conditions of good conductivity and high reflectivity are satisfied, and the materials may be specifically set according to actual needs.
As an example, the metal module cross section of the metal array layer 70 has one or more of a circular shape, a square shape and a regular hexagon shape.
In this embodiment, because the circle is easy to process, the cross section of the metal module is preferably a circle, the circumscribing circle of the circle is self, and then the radius of the circumscribing circle is also the radius of the circle itself. In addition, when the cross section of the metal module is square, the radius of the circumscribed circle is the radius of the diagonal line, and when the cross section of the metal module is regular hexagon, the radius of the circumscribed circle is the radius of the diagonal line. The shapes of the metal modules of the metal array layer 70 may be identical, or may be a combination of the above patterns, and the shapes preferably adopted in this embodiment are identical, so as to facilitate the calculation of the radius of the metal modules of the metal array layer 70 and the calculation of the array period.
Based on the above, as shown in fig. 2, in this embodiment, the material of the metal reflective layer 40 and the metal array layer 70 is aluminum, the material of the dielectric layer 50 is germanium, wherein the shape of the cross section of the metal module in the metal array layer 70 is circular, so as to form the MIM absorber with an aluminum reflective layer-germanium layer-aluminum disk array layer structure, wherein the dielectric layer 50 in the MIM absorber is not particularly required, as long as it is a semiconductor material and has a thickness not greater than wavelength/4 n, where n is the refractive index of the dielectric layer 50, and in this embodiment, a conventional germanium material is selected.
As shown in fig. 3, as an example, in the absorption spectrum of the MIM absorber of the aluminum reflective layer-germanium layer-aluminum disk array layer structure, the array period of the aluminum disk array layer is 2 μm. The respective infrared absorption ranges are when the radius of the aluminum disc is 0.57 μm, i.e. 570nm, the radius of the aluminum disc is 0.6 μm, i.e. 600nm, the radius of the aluminum disc is 0.64 μm, i.e. 640nm, and the radius of the aluminum disc is 0.68 μm, i.e. 680 nm.
It can be seen from the figure that the radius of the aluminum disc is in the range of 0.5 μm to 0.7 μm and can cover the wavelength that absorbs the entire long-wave infrared, i.e. 8 μm to 14 μm.
By way of example, the radius of the aluminum disks in the aluminum disk array layer is preferably 0.6 μm, and the array period of the aluminum disk array layer 70 is preferably 2 μm, that is, the distance between centers of adjacent two aluminum disks is 2 μm. The thickness range of the aluminum disc array layer is 40-60 nm, the thickness range of the germanium layer is 120-180 nm, and the thickness range of the aluminum reflecting layer is 120-180 nm; as an example, the thickness of the aluminum disk array layer is preferably 50nm, the thickness of the germanium layer is 150nm, and the thickness of the aluminum reflection layer is 150nm.
In the long-wave infrared thermoelectric detector based on the absorber of the aluminum reflecting layer-germanium layer-aluminum disc array layer structure, only one array can be arranged in the aluminum disc array layer, wherein the radius of the aluminum disc is set to be 0.6 mu m, the array period is set to be 2 mu m, and only infrared rays with single wavelength can be absorbed; a plurality of regular arrays may be disposed in the aluminum disc array layer, wherein the radii of the aluminum discs in different arrays are set to 0.57 μm, 0.6 μm, 0.64 μm and 0.68 μm, and the array periods are set to 2 μm, which are commonly used for absorbing infrared rays of different wavelengths, and covering the entire long-wave infrared range, so as to increase the detection wavelength range of the long-wave infrared detector.
As an example, the materials of the upper electrode 30 and the lower electrode 20 are the same, and the materials of the upper electrode 30 and the lower electrode 20 are one of chromium, platinum, nickel, and titanium.
The materials of the upper electrode 30 and the lower electrode 20 are not limited to the above materials, and may be specifically set according to actual needs as long as the conditions of good adhesion and small work function are satisfied.
As an example, the upper electrode 30 and the lower electrode 20 are in ohmic contact with the thermoelectric conversion layer 10.
As an example, the seebeck coefficient range of the material of the thermoelectric conversion layer 10 is > 50uV/K, and as long as this condition is satisfied, the selection of the specific material may be set according to actual needs, and no limitation is made here.
The thermoelectric conversion layer 10 has a material with a Seebeck coefficient S of large, a photo-thermal effect and good conductivity, and is usually made of carbon nanotubes or Bi 2 Te 3 、Sb 2 Te 3 SrTiO 3 Etc. The larger the seebeck coefficient S is, the larger the response voltage U that the thermoelectric conversion layer 10 can obtain is; the smaller the thickness of the thermoelectric conversion layer 10 is, the smaller the response time is, and the smaller the temperature difference Δt is, but the thickness cannot be excessively small because the smaller the thickness is, the response voltage U is also affected; as can be seen from the formula response voltage u=seebeck coefficient s×temperature difference Δt, if seebeck coefficient S is large, temperature difference Δt may be slightly smaller, i.e., may be thinner in thickness.
Example two
The present embodiment provides a method for preparing a MIM absorber-based long-wave infrared thermoelectric detector, which may be used to prepare a MIM absorber-based long-wave infrared thermoelectric detector according to the first embodiment, and the method for preparing a MIM absorber-based long-wave infrared thermoelectric detector according to the second embodiment is described in detail below with reference to fig. 4 to 13.
As shown in fig. 4S1 and 5, first, step S1 is performed to provide the thermoelectric conversion layer 10.
The thermoelectric conversion layer 10 can be used as a substrate of a long-wave infrared thermal detector based on an MIM absorber, the thermoelectric conversion layer 10 has a Seebeck coefficient of at least 50uV/K, a photo-thermal effect and good conductivity, and the common materials include carbon nanotubes and Bi 2 Te 3 、Sb 2 Te 3 SrTiO 3 Etc. .
As shown in fig. 4S2 and fig. 6 to 7, next, step S2 is performed to form an upper electrode 30 and a lower electrode 20 on the upper and lower surfaces of the thermoelectric conversion layer 10, respectively.
In this embodiment, the materials of the lower electrode 20 and the upper electrode 30 are the same, and are all metal chromium materials, and a layer of chromium film is deposited on the upper and lower surfaces of the thermoelectric conversion layer 10 by using electron beam evaporation or thermal evaporation technology. A chromium film may be deposited on the upper surface of the thermoelectric conversion layer 10, and then a chromium film may be deposited on the lower surface of the thermoelectric conversion layer 10; a chromium film may be deposited on the lower surface of the thermoelectric conversion layer 10 (as shown in fig. 6), and then a chromium film may be deposited on the upper surface of the thermoelectric conversion layer 10 (as shown in fig. 7); the sequence is not limited, but based on the easiness of the preparation process, it is preferable to deposit a chromium film on the lower surface of the thermoelectric conversion layer 10 before depositing a chromium film on the upper surface of the thermoelectric conversion layer 10, so that the thermoelectric conversion layer 10 is reversed only once.
After the chromium films are respectively deposited on the upper and lower surfaces of the thermoelectric conversion layer 10, the same sides of the two chromium films may be directly etched to form the lower electrode 20 and the upper electrode 30. The lower electrode 20 and the upper electrode 30 may be formed by using a photolithography and etching process, that is, a layer of photoresist is coated on the upper and lower surfaces of the thermoelectric conversion layer 10, a pattern exposure treatment is performed, then a chromium film is deposited by using an electron beam evaporation or thermal evaporation technique, and finally the photoresist in the unexposed area and the chromium film deposited in the area are stripped to obtain the lower electrode 20 and the upper electrode 30.
As shown in fig. 4S3 and 8, step S3 is performed to form a metal reflective layer 40 on the surface of the upper electrode 30.
In this embodiment, the material of the metal reflective layer 40 is preferably a metal aluminum material, and a layer of aluminum film is deposited on the surface of the upper electrode 30 to form an aluminum reflective layer, wherein the aluminum reflective layer does not completely cover the upper surface of the upper electrode 30, leaving a portion of the upper electrode 30 (as shown in fig. 1) that needs to be exposed on the side, and the thickness of the aluminum reflective layer is 150nm, that is, the thickness of the deposited aluminum film is 150nm.
As shown in fig. 4S4 and 9, step S4 is performed to form a dielectric layer 50 on the surface of the metal reflective layer 40.
In this embodiment, the material of the dielectric layer 50 is not particularly limited, and a conventional germanium material is used. And depositing a germanium film on the upper surface of the aluminum reflecting layer to form a germanium layer, wherein the thickness of the germanium layer is 150nm, namely the thickness of the deposited germanium film is 150nm.
As shown in fig. 4S4 and fig. 10 to 13, finally, step S5 is performed: a metal array layer 70 is formed on the surface of the dielectric layer 50.
Forming a photoresist layer 60 (as shown in fig. 10) on the upper surface of the above structure, wherein the photoresist layer 60 covers the surface of the dielectric layer 50 and also covers the exposed surface of the upper electrode 30, so as to protect the upper electrode 30 during forming the metal array layer 70, and performing a pattern exposure treatment to obtain a pattern mask layer 61 (as shown in fig. 11), wherein the metal array layer 70 can be prepared in this step, no matter how many arrays are arranged, as long as the preset pattern mask layer 61 is prepared in advance; a metal film is deposited on the pattern mask layer 61 (as shown in fig. 12), and metal is stripped to obtain the metal array layer 70 (as shown in fig. 13), wherein the solution used in the metal stripping process is one of acetone and PGR above.
In this embodiment, the metal array layer 70 is preferably made of metal aluminum, and the cross-sectional shape of the metal module is preferably circular. And forming a photoresist layer 60 on the surface of the structure, wherein the photoresist layer 60 covers the upper surface of the germanium layer, and also covers the exposed surface of the upper electrode 30 to protect the upper electrode 30, performing pattern exposure treatment to obtain a mask layer with a circular pattern, depositing a layer of aluminum film on the circular mask layer, and performing metal stripping to obtain an aluminum disc array layer, wherein the thickness of the aluminum disc array layer is 50nm, namely the thickness of the deposited aluminum film is 50nm.
In summary, the present invention provides a MIM absorber-based long-wave infrared thermoelectric detector and a method for manufacturing the same, where the MIM absorber-based long-wave infrared thermoelectric detector includes: a thermoelectric conversion layer for thermoelectric conversion; an upper electrode and a lower electrode respectively arranged on the upper surface and the lower surface of the thermoelectric conversion layer; the MIM absorber is arranged on the surface of the upper electrode and is used for absorbing photons and converting the photons into heat energy, and the area of the MIM absorber is smaller than that of the thermoelectric conversion layer; the MIM absorber sequentially comprises a metal reflecting layer, a dielectric layer and a metal array layer, wherein the metal reflecting layer is arranged on the surface of the upper electrode, the metal reflecting layer is made of the same material as the metal array layer, the metal array layer is formed by periodically arranging a plurality of regular metal modules in a central symmetry mode, and the radius range of a circumscribed circle of the cross section of each metal module is 0.5-0.7 mu m; the array period of the metal array layer ranges from 1.5 mu m to 2.5 mu m. According to the invention, 100% perfect absorption of photons is realized by means of the MIM absorber, and the absorbed photons are limited on the upper surface of the thermoelectric conversion layer by utilizing the metal reflection layer, so that the temperature difference is generated on the upper surface and the lower surface of the thermoelectric conversion layer, the channel length between two electrodes is reduced, and the response time is shortened; the invention regulates and controls the absorption bandwidth and the absorption peak wavelength by the size of the metal module in the metal array layer and the array period; in addition, the material of the invention has low cost and simple preparation process, can realize large-area preparation and is easy to popularize. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.
Claims (10)
1. A MIM absorber-based long wave infrared light pyroelectric detector, the MIM absorber-based long wave infrared light pyroelectric detector comprising:
a thermoelectric conversion layer for thermoelectric conversion;
an upper electrode and a lower electrode respectively arranged on the upper surface and the lower surface of the thermoelectric conversion layer;
the MIM absorber is arranged on the surface of the upper electrode and is used for absorbing photons and converting the photons into heat energy, and the area of the MIM absorber is smaller than that of the thermoelectric conversion layer;
the MIM absorber sequentially comprises a metal reflecting layer, a dielectric layer and a metal array layer, wherein the metal reflecting layer is arranged on the surface of the upper electrode, the metal reflecting layer is made of the same material as the metal array layer, the metal array layer is formed by periodically arranging a plurality of regular metal modules in a central symmetry mode, the radius range of a circumscribed circle of the cross section of each metal module is 0.5-0.7 mu m, and the array period range of the metal array layer is 1.5-2.5 mu m.
2. The MIM absorber-based long wave infrared photo-detector of claim 1, wherein: the number of arrays in the metal array layer is more than or equal to 1; when the number of arrays in the metal array layer is 1, the radius of the circumscribed circle of the cross section of the metal module is completely the same, and the metal module is used for absorbing infrared rays with single wavelength; when the number of the arrays in the metal array layer is more than 1, the radius of the circumscribed circles of the cross sections of the metal modules of different arrays is different and the metal modules are used for absorbing infrared rays with different wavelengths.
3. The MIM absorber-based long wave infrared photo-detector of claim 1, wherein: the metal reflecting layer and the metal array layer in the MIM absorber are made of one or more than two of aluminum, gold, silver and copper.
4. The MIM absorber-based long wave infrared photo-detector of claim 3, wherein: the cross section of the metal module of the metal array layer is in the shape of one or more than two of a circle, a square and a regular hexagon.
5. The MIM absorber-based long wave infrared photo-detector of claim 4, wherein: the metal reflecting layer and the metal array layer in the MIM absorber are made of aluminum, the dielectric layer is made of germanium, and the cross section of the metal module in the metal array layer is round, so that the MIM absorber with an aluminum reflecting layer-germanium layer-aluminum disc array layer structure is formed.
6. The MIM absorber-based long wave infrared photo-detector of claim 5, wherein: the thickness range of the aluminum disc array layer is 40-60 nm, the thickness range of the germanium layer is 120-180 nm, and the thickness range of the aluminum reflecting layer is 120-180 nm.
7. The MIM absorber-based long wave infrared photo-detector of claim 1, wherein: the upper electrode and the lower electrode are made of the same material, and the upper electrode and the lower electrode are made of one of chromium, platinum, nickel and titanium.
8. The MIM absorber-based long wave infrared photo-detector of claim 1, wherein: the upper electrode and the lower electrode are in ohmic contact with the thermoelectric conversion layer.
9. The MIM absorber-based long wave infrared photo-detector of claim 1, wherein: the Seebeck coefficient range of the thermoelectric conversion layer material is more than 50uV/K.
10. A method for manufacturing a MIM absorber-based long wave infrared pyroelectric detector according to any one of claims 1 to 9, wherein the method comprises:
s1: providing a thermoelectric conversion layer;
s2: forming an upper electrode and a lower electrode on the upper surface and the lower surface of the thermoelectric conversion layer respectively;
s3: forming a metal reflecting layer on the surface of the upper electrode;
s4: forming a dielectric layer on the surface of the metal reflecting layer;
s5: and forming a metal array layer on the surface of the dielectric layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210841060.0A CN117479808A (en) | 2022-07-18 | 2022-07-18 | MIM absorber-based long-wave infrared thermoelectric detector and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210841060.0A CN117479808A (en) | 2022-07-18 | 2022-07-18 | MIM absorber-based long-wave infrared thermoelectric detector and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117479808A true CN117479808A (en) | 2024-01-30 |
Family
ID=89636577
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210841060.0A Pending CN117479808A (en) | 2022-07-18 | 2022-07-18 | MIM absorber-based long-wave infrared thermoelectric detector and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117479808A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117812985A (en) * | 2024-03-01 | 2024-04-02 | 中北大学 | Flexible photo-thermal electric detection device based on spraying method and preparation method thereof |
-
2022
- 2022-07-18 CN CN202210841060.0A patent/CN117479808A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117812985A (en) * | 2024-03-01 | 2024-04-02 | 中北大学 | Flexible photo-thermal electric detection device based on spraying method and preparation method thereof |
| CN117812985B (en) * | 2024-03-01 | 2024-05-14 | 中北大学 | Flexible photo-thermal electric detection device based on spraying method and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5367167A (en) | Uncooled infrared detector and method for forming the same | |
| EP0534768B1 (en) | Uncooled infrared detector and method for forming the same | |
| US5479018A (en) | Back surface illuminated infrared detector | |
| US11710801B2 (en) | Silicon carbide-based full-spectrum-responsive photodetector and method for producing same | |
| US8897609B1 (en) | Frequency selective infrared sensors | |
| Forbes | Texturing, reflectivity, diffuse scattering and light trapping in silicon solar cells | |
| JP6918631B2 (en) | Photodetector | |
| CA1269164A (en) | Photosensitive diode with hydrogenated amorphous silicon layer | |
| US4575631A (en) | Infra-red detector | |
| JP2012151452A (en) | Photodetector optimized by metal texturing provided on rear surface | |
| CN117479808A (en) | MIM absorber-based long-wave infrared thermoelectric detector and preparation method thereof | |
| CN110943138B (en) | Colloidal quantum dot infrared focal plane array based on interference enhancement structure and preparation method | |
| Zhou et al. | A compact polarization-integrated long wavelength infrared focal plane array based on InAs/GaSb superlattice | |
| CN113340436B (en) | Uncooled CMOS infrared detector | |
| CN112331737B (en) | Ultraviolet-visible-near infrared silicon-based photoelectric detector and preparation method thereof | |
| US20220155150A1 (en) | Infrared absorption and detection enhancement using plasmonics | |
| CN113720472B (en) | Infrared detector based on CMOS (complementary Metal oxide semiconductor) process | |
| CN113447140B (en) | CMOS infrared microbridge detector | |
| US6359283B1 (en) | Noise reduced photon detector | |
| CN113447150A (en) | Infrared detector with microbridge structure | |
| CN113432727A (en) | Non-refrigeration solid focal plane detector | |
| US11788893B1 (en) | Nanoscale bolometer operating near the thermodynamic limit | |
| CN113432726A (en) | Infrared detector with combined columnar structure | |
| Green | Surface texturing and patterning in solar cells | |
| US11652119B2 (en) | Detection component including black pixels and method for manufacturing such a component |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |