Modeling of a Tandem Solar Cell Structure Based on CZTS and CZTSe Absorber Materials

EasyChair Preprint 3772

Abstract

İn this paper a kestrite double junction tandem solar cell based on a CdS/Cu₂ZnSnS₄ top cell stacked on CdS/Cu₂ZnSnSe₄ bottom cell has been simulated. Firstly, the performance of the bottom cell was investigated against the variation of the CZTSe absorber thickness. The performance of the tandem cell was determined according to the optimized CZTS top cell absorber thickness for which current match condition of top and bottom sub cells is reached. A maximum efficiency of 24.68 % with 1.33 V open circuit voltage was achieved for 16.54 mA/cm² density of current, 413.8 nm thick CZTS top cell absorber and 2µm thick CZTSe bottom cell absorber. İn order to improve power conversion efficiency, light trapping effects have been investigated in this work. The use of back mirror in the bottom sub cell has led to a double absorption in the CZTSe layer allowing the increase of efficiency up to 24.8%. This work also demonstrated that the use of randomly textured top cell absorber allows the reduction of its thickness to 270 nm. An efficiency of 24.71% was than obtained. Finally, the effect of replacing the toxic CdS buffer absorber with the ZnS material was investigated.

Keyphrases: CZTS, CZTSe, Kestrite, Photovoltaic device, Tandem Solar Cell

@booklet{EasyChair:3772,
  author    = {Hayat Arbouz},
  title     = {Modeling of a Tandem Solar Cell Structure Based on CZTS and CZTSe Absorber Materials},
  howpublished = {EasyChair Preprint 3772},
  year      = {EasyChair, 2020}}