Study of Graded Ultrathin CIGS/Si Structure for Solar Cell Applications
Résumé
This paper aims to improve the performance of graded ultrathin CIGS-based solar cells using the one-dimensional simulation program (SCAPS-1D). In this context, we have assessed the effect of the graded bandgap and the thickness of the absorber layer (CIGS) on solar cell performance. We have also examined the impact of different graded bandgap profiles by varying the gallium concentration. Notably, the increase of the gallium concentration (xGa) and the CIGS thickness (dCIGS) have degraded the conversion efficiency η. The optimization of these parameters gives a considerable solar yield when dCIGS = 1 μm and xGa in the range 0.1–0.3. For the graded cell, we have mentioned that the double-graded profile improves significantly the conversion efficiency up to 22.21% compared to the uniform profile with η = 21.43%.