The production of high-performance, solution-processed kesterite Cu2ZnSn(Sx,Se1-x)4 (CZTSSe) solar cells typically relies on high-temperature crystallization processes in chalcogen-containing atmosphere and often on the use of environmentally harmful solvents, which could hinder the widespread adoption of this technology. We report a method for processing selenium free Cu2ZnSnS4 (CZTS) solar cells based on a short annealing step at temperatures as low as 350 °C using a molecular based precursor, fully avoiding highly toxic solvents and high-temperature sulfurization. We show that a simple device structure consisting of ITO/CZTS/CdS/Al and comprising an extremely thin absorber layer (∼110 nm) achieves a current density of 8.6 mA/cm(2). Over the course of 400 days under ambient conditions encapsulated devices retain close to 100% of their original efficiency. Using impedance spectroscopy and photoinduced charge carrier extraction by linearly increasing voltage (photo-CELIV), we demonstrate that reduced charge carrier mobility is one limiting parameter of low-temperature CZTS photovoltaics. These results may inform less energy demanding strategies for the production of CZTS optoelectronic layers compatible with large-scale processing techniques.
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http://dx.doi.org/10.1021/acsami.5b04468 | DOI Listing |
Adv Mater
November 2024
Institute of Thin Film Physics and Applications, Shenzhen Key Laboratory of Advanced Thin Films and Applications, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, State Key Laboratory of Radio Frequency Heterogeneous Integration, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China.
The major challenge in preparing high-performance CuZnSn(S,Se) solar cells is the large open circuit voltage deficit (V-def). A new strategy utilizing the synergistic substitution of Ag and In dual cations has been proposed to simultaneously address the problems of undesirable interface band alignment and high-density detrimental bulk defects, obtaining decreased carrier recombination rate and increased minority carrier lifetime. The shorter In-S/Se bonds move the CBM higher by generating stronger repulsive force than the Sn-S/Se bonds, thus adjusting the interface band alignment.
View Article and Find Full Text PDFSmall
August 2024
Shenzhen Key Laboratory of Advanced Thin Films and Applications, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, State Key Laboratory of Radio Frequency Heterogeneous Integration, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, 518060, China.
CuZnSn (S,Se) (CZTSSe), a promising absorption material for thin-film solar cells, still falls short of reaching the balance limit efficiency due to the presence of various defects and high defect concentration in the thin film. During the high-temperature selenization process of CZTSSe, the diffusion of various elements and chemical reactions significantly influence defect formation. In this study, a NaOH-Se intermediate layer introduced at the back interface can optimize CuZnSnS (CZTS)precursor films and subsequently adjust the Se and alkali metal content to favor grain growth during selenization.
View Article and Find Full Text PDFNanoscale
May 2023
Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Centre for High-efficiency Display and Lighting Technology, School of Materials, Collaborative Innovation Centre of Nano Functional Materials and Applications, Henan University, Kaifeng, 475004, China.
Solar cells based on emerging kesterite CuZnSn(S,Se) (CZTSSe) materials have reached certified power conversion efficiency (PCE) as high as 13.6%, showing great potential in the next generation of photovoltaic technologies because of their earth-abundant, tunable direct bandgap, high optical absorption coefficient, environment-friendly, and low-cost properties. The predecessor of CZTSSe is Cu(In,Ga) Se (CIGS), and the highest PCE of CIGS fabricated by the vacuum method is 23.
View Article and Find Full Text PDFACS Appl Mater Interfaces
March 2023
Shenzhen Key Laboratory of Advanced Thin Films and Applications, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, Guangdong, P. R. China.
Kesterite-based CuZnSnS (CZTS) thin-film photovoltaics involve a serious interfacial dilemma, leading to severe recombination of carriers and insufficient band alignment at the CZTS/CdS heterojunction. Herein, an interface modification scheme by aluminum doping is introduced for CZTS/CdS via a spin coating method combined with heat treatment. The thermal annealing of the kesterite/CdS junction drives the migration of doped Al from CdS to the absorber, achieving an effective ion substitution and interface passivation.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
September 2023
Department of Physics, Banasthali Vidyapith, Jaipur, Rajasthan, 304022, India.
Using zinc tellurium (ZnTe) as the buffer layer in the CuZnSnS (CZTS)-based solar cells showed an improvement in overall efficiency. ZnTe is investigated as an alternative to replace the conventional toxic Cd-contained buffer layers. It may also reduce the overall cost of these cells as both layers (ZnTe and CZTS) have eco-friendly and earth-abundant constituents.
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