Numerical analysis of graded band gap CZT(S,Se) solar cells using AMPS-1D

The one-dimensional simulation program called Analysis of Microelectronic and Photonic Structures (AMPS-1D), was used to simulate the performance of some novel solar cell structures. The cells based on Copper-zinc-tin-sulphide (selenide), Cu2ZnSn(S,Se)4 as absorber layer, cadmium sulfide (CdS) as a buffer layer , un-doped ZnO (i-ZnO) and F-doped SnO2 (FTO) as a window layer. The effect of grading the band gap through changing the value of x in the composition CZTSX, Se1-X is investigated. Improved performance, in terms of efficiency was observed. An efficiency of about 30% for a graded-band cell is reported relative to non-graded cells where the efficiencies are around 20%.