How to control the stoichiometry of cadmium telluride thin film for photovoltaic applications
| Autor: | Chuanjun Zhang, B. Siepchen, Alan E. Delahoy, Shou Peng, Akash Saraf, Ken K. Chin, Jingong Pan, V. Krishnakumar, Xuehai Tan, Shenjiang Xia, Guogen Liu |
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| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science Renewable Energy Sustainability and the Environment Photovoltaic system Analytical chemistry 02 engineering and technology Growth model Partial pressure 021001 nanoscience & nanotechnology 01 natural sciences Cadmium telluride photovoltaics Physical vapor deposition 0103 physical sciences Sublimation (phase transition) Thin film 0210 nano-technology Stoichiometry |
| Zdroj: | Journal of Renewable and Sustainable Energy. 9:063505 |
| ISSN: | 1941-7012 |
| DOI: | 10.1063/1.4995655 |
| Popis: | In this study, Bube's growth model for a cadmium telluride (CdTe) polycrystalline thin film was re-examined with a view of avoiding his assumptions that neglect the vapor pressures of Cd and Te2 near the film. We proposed a new thermodynamic growth model based on the fact that there is an experimentally verified characteristic ratio (α) of equilibrium partial pressures PCd/2PTe2 that depends on the temperature T and CdTe stoichiometry. By writing PCd(0)=2α(0)PTe2(0) and PCd(h)=2α(h)PTe2(h), where α(0) is determined by source stoichiometry, we can solve the equations for α(h) and thereby determine the stoichiometry of the CdTe thin film grown under physical vapor deposition (PVD) conditions. Simulation was performed to predict the stoichiometry of the CdTe thin film as a function of source stoichiometry for various source-film temperature combinations. The results show that for a typical CdTe PVD process with Tsource>Tthin film: (1) stable deposition, without a non-stoichiometric composition shift, can be ... |
| Databáze: | OpenAIRE |
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