Simulation of CZTS-based thin-film solar cells (Simulation des cellules solaires en couches minces à base de CZTS)

Abstract

Cu2ZnSnS4 (CZTS), is a quaternary semiconductor of the thin film with a direct band-gap, has a gap of 1.6-1.4 eV with a large absorption coefficient of 104 cm-1, a film absorber with very beneficial properties, in addition to its low production cost. In this work, the effect of many parameters of the absorber layer on the performance of a CZTS solar cell is investigated using the numerical simulation program SCAPS-1D. Also the effect of defects type (donor and acceptor) deep in the band gap of the CZTS was studied. The series and shunt resistances and the interface defects between layer P and layer N were also considered. The effect of the band-gap of energy, thickness, acceptor density and electron affinity were also highlighted. The performance of the solar cell was studied in terms of the short circuit current Jsc, the open-circuit voltage Voc, the fill factor FF, and the efficiency ɳ. It was found that when volume defects are considered in the CZTS absorber layer, better results were obtained but not as expected; only the short circuit current is reproduced. On the other hand, interface states are considered between CZTS and CdS give good agreement of the open circuit voltage. The series and shunt resistance lead to a better agreement of the fill factor. Only when all these are considered together that experimental measurements are reproduced.