Search

CN-122028554-A - CdTe thin film photovoltaic cell based on composite window layer and preparation method thereof

CN122028554ACN 122028554 ACN122028554 ACN 122028554ACN-122028554-A

Abstract

The invention discloses a CdTe thin film photovoltaic cell based on a composite window layer and a preparation method thereof, and belongs to the technical field of photovoltaic devices; the composite window layer is formed by compositing a CdS layer, a CdSeO 4 layer and a ZnS layer. According to the invention, the triple-function synergistic effect of energy level matching-ion blocking-light transmission is realized by introducing CdS/CdSeO 4 /ZnS multi-layer composite window layers, so that the photoelectric performance and stability of the CdTe thin film photovoltaic cell are improved.

Inventors

  • SHI QINCHANG
  • ZHANG YANNING
  • MA QIANQIAN

Assignees

  • 中茂绿能科技(西安)有限公司

Dates

Publication Date
20260512
Application Date
20260211

Claims (8)

  1. 1. A CdTe thin film photovoltaic cell based on a composite window layer is characterized by sequentially comprising a transparent conductive substrate, a composite window layer, a CdTe absorption layer, a ZnTe interface modification layer and a metal back electrode from bottom to top, wherein the composite window layer is formed by compositing a CdS layer, a CdSeO 4 layer and a ZnS layer, the CdS layer is positioned above the transparent conductive substrate, the CdSeO 4 layer is positioned between the CdS layer and the ZnS layer, and the ZnS layer is positioned below the CdTe absorption layer.
  2. 2. The CdTe thin-film photovoltaic cell based on the composite window layer according to claim 1, wherein the thickness of the CdS layer is 35-55 nm, the thickness of the CdSeO 4 layer is 20-30 nm, and the thickness of the ZnS layer is 5-8 nm.
  3. 3. The CdTe thin-film photovoltaic cell based on the composite window layer according to claim 1, wherein the transparent conductive substrate is any one of FTO/ITO conductive glass or ITO flexible PET substrate, the square resistance is less than or equal to 10Ω/≡, the light transmittance is more than or equal to 88%, the thickness of the CdTe absorption layer is 1.8-2.2 μm, the thickness of the ZnTe interface modification layer is 5-8 nm, and the thickness of the metal back electrode is 200-300 nm, and is any one of a Cu/Au composite electrode or a Mo electrode.
  4. 4. A method for preparing the CdTe thin film photovoltaic cell based on the composite window layer according to any one of claims 1 to 3, comprising the following steps: pretreating the transparent conductive substrate to obtain a pretreated transparent conductive substrate; The pretreated transparent conductive substrate is put into a precursor solution of CdS, and a CdS layer is formed through chemical bath deposition reaction; depositing CdSeO 4 material on the CdS layer to form a CdSeO 4 layer; Depositing ZnS material on the CdSeO 4 layer to form a ZnS layer; Depositing an absorption layer material on the ZnS layer, and then annealing in an inert atmosphere to form a CdTe absorption layer; depositing an interface modification layer material on the CdTe absorption layer to form a ZnTe interface modification layer; and depositing a metal back electrode material on the ZnTe interface modification layer to form a metal back electrode, thereby obtaining the CdTe thin film photovoltaic cell based on the composite window layer.
  5. 5. The preparation method of the CdTe thin-film photovoltaic cell based on the composite window layer, which is disclosed in claim 4, is characterized in that the precursor solution of CdS comprises 0.03mol/L cadmium nitrate and 0.08mol/L thiourea, the temperature of the chemical bath deposition reaction is 60-70 ℃, and the reaction time is 20-25 min.
  6. 6. The preparation method of the CdTe thin-film photovoltaic cell based on the composite window layer, which is disclosed in claim 4, is characterized in that the deposition method adopted for forming the CdTe absorbing layer is a near-space sublimation method or an electrospray deposition method, the annealing temperature of the annealing treatment is 380-400 ℃, the annealing time is 20-25 min, the deposition methods adopted for forming CdSeO 4 layers, znS layers and ZnTe interface modification layers are all magnetron sputtering methods, and the deposition method adopted for forming the metal back electrode is a thermal evaporation method or a magnetron sputtering method.
  7. 7. The method for preparing the CdTe thin-film photovoltaic cell based on the composite window layer, which is disclosed by claim 4, is characterized by further comprising post-treatment and packaging, wherein the post-treatment and packaging method comprises the steps of placing the obtained CdTe thin-film photovoltaic cell based on the composite window layer in an annealing furnace with a nitrogen atmosphere of 110-120 ℃ for 10-15 min, cooling to room temperature, and scribing to form an independent battery unit for packaging.
  8. 8. The method for preparing the CdTe thin-film photovoltaic cell based on the composite window layer according to claim 7, wherein the packaging temperature is 120-140 ℃ and the packaging pressure is 0.08-0.12 MPa.

Description

CdTe thin film photovoltaic cell based on composite window layer and preparation method thereof Technical Field The invention belongs to the technical field of photovoltaic devices, and particularly relates to a CdTe thin film photovoltaic cell based on a composite window layer and a preparation method thereof. Background The CdTe thin film photovoltaic cell adopts a structure that light is incident from the transparent conductive substrate, so that light absorption loss can be reduced, and short circuit current density can be improved. The window layer of the existing CdTe thin film photovoltaic cell mostly adopts a single-layer CdS or CdS/CdSe double-window layer structure, and the problems of low energy level matching degree, weak ion diffusion blocking capability, multiple interface defects and the like exist, so that the open circuit voltage and the filling factor of the CdTe thin film photovoltaic cell are limited to be improved, and the long-term stability is difficult to meet the commercialized requirements. Disclosure of Invention Aiming at the defects existing in the prior art, the application provides the CdTe thin film photovoltaic cell based on the composite window layer and the preparation method thereof, and the CdS/CdSeO 4/ZnS multi-layer composite window layer is introduced to realize the triple-function synergistic effect of energy level matching-ion blocking-light transmission, so that the photoelectric performance and stability of the CdTe thin film photovoltaic cell are improved. The invention aims to provide a CdTe thin film photovoltaic cell based on a composite window layer, which sequentially comprises a transparent conductive substrate, a composite window layer, a CdTe absorption layer, a ZnTe interface modification layer and a metal back electrode from bottom to top, wherein the composite window layer is formed by compositing a CdS layer, a CdSeO 4 layer and a ZnS layer, the CdS layer is positioned above the transparent conductive substrate, the CdSeO 4 layer is positioned between the CdS layer and the ZnS layer, and the ZnS layer is positioned below the CdTe absorption layer. According to the invention, the CdS/CdSeO 4/ZnS composite structure is adopted as the composite window layer of the CdTe thin film photovoltaic cell to realize the synergistic effect of the three functions of energy level matching, ion blocking and light transmission, so that the photoelectric performance and stability of the CdTe thin film photovoltaic cell are improved. The CdS layer is positioned above the transparent conductive substrate and is directly contacted with the transparent conductive substrate, the forbidden bandwidth is 2.4-2.6 eV, the transparent conductive substrate has excellent light transmittance and conductivity, so that the contact potential barrier between the transparent conductive substrate and the window layer of the substrate is reduced, carrier interface recombination is reduced, the CdSeO 4 layer is used as an intermediate energy level matching layer, the forbidden bandwidth is 2.7-2.9 eV, the energy level step transition between the CdS layer and the ZnS layer is realized, a high-efficiency carrier transmission channel is constructed, the visible light transmittance is improved, the ZnS layer is positioned below the CdTe absorbing layer and is directly contacted with the CdTe absorbing layer, the compactness is more than or equal to 98%, the Cd2+ diffusion coefficient is less than or equal to 3× -11 cm < 2 >/s, the Gao Jindai width is 3.5-3.7 eV, the light absorption loss can be reduced, and the migration of Cd2+ to the window layer is blocked, so that the environmental protection safety and the long-term stability of the battery are improved. Further, the thickness of the CdS layer is 35-55 nm, the thickness of the CdSeO 4 layer is 20-30 nm, and the thickness of the ZnS layer is 5-8 nm. Further, the transparent conductive substrate is any one of FTO/ITO conductive glass or ITO flexible PET substrate, the square resistance is less than or equal to 10Ω/≡, the light transmittance is more than or equal to 88%, the thickness of the CdTe absorption layer is 1.8-2.2 μm, the thickness of the ZnTe interface modification layer is 5-8 nm, the thickness of the metal back electrode is 200-300 nm, and the metal back electrode is any one of a Cu/Au composite electrode or a Mo electrode. The second object of the invention is to provide a preparation method of the CdTe thin film photovoltaic cell based on the composite window layer, which comprises the following steps: pretreating the transparent conductive substrate to obtain a pretreated transparent conductive substrate; The pretreated transparent conductive substrate is put into a precursor solution of CdS, and a CdS layer is formed through chemical bath deposition reaction; depositing CdSeO 4 material on the CdS layer to form a CdSeO 4 layer; Depositing ZnS material on the CdSeO 4 layer to form a ZnS layer; Depositing an absorption layer m