Effects of Cd1-xZnxS alloy composition and post-deposition air anneal on ultra-thin CdTe solar cells produced by MOCVD

Ultra-thin CdTe:As/Cd1-xZnxS photovoltaic solar cells with an absorber thickness of 0.5 μm were deposited by metal-organic chemical vapour deposition on indium tin oxide coated boro-aluminosilicate substrates. The Zn precursor concentration was varied to compensate for Zn leaching effects after CdCl2 activation treatment. Analysis of the solar cell composition and structure by X-ray photoelectron spectroscopy depth profiling and X-ray diffraction showed that higher concentrations of Zn in the Cd1-xZnxS window layer resulted in suppression of S diffusion across the CdTe/Cd1-xZnxS interface after CdCl2 activation treatment. Excessive Zn content in the Cd1-xZnxS alloy preserved the spectral response in the blue region of the solar spectrum, but increased series resistance for the solar cells. A modest increase in the Zn content of the Cd1-xZnxS alloy together with a post-deposition air anneal resulted in an improved blue response and an enhanced open circuit voltage and fill factor. This device yielded a mean efficiency of 8.3% over 8 cells (0.25 cm2 cell area) and best cell efficiency of 8.8%.

CLAYTON Andrew;  BAKER M.A.;  BABAR S.;  GRILLI Rossana;  GIBSON Peter;  KARTOPU G.;  LAMB D. A.;  BARRIOZ V.;  IRVINE S. J. C.; 

2017-03-21

ELSEVIER SCIENCE SA

JRC96048

0254-0584,   

http://dx.doi.org/10.1016/j.matchemphys.2017.01.067,    https://publications.jrc.ec.europa.eu/repository/handle/JRC96048,   

10.1016/j.matchemphys.2017.01.067,