Numerical analysis on prospects of high efficiency CdS/CdTe thin film solar cell

Abstract

Photovoltaic (PV) energy is one of the significant renewable energies with free and permanent resource. Cadmium Telluride (CdTe) is from group II-VI of compound polycrystalline semiconductors. The CdTe solar cell material can be produced in thinness of film; hence, it is very appropriate for thin film solar cell industry production. The main purpose of this investigation is to model and analyze a prospect structure of thin film CdTe solar cell by AMPS-1D software. In this solar cell structure, Thin Oxide (SnO 2 ) as front contact, Cadmium Sulfide (CdS) as window layer, CdTe as absorber layer and Molybdenum (Mo) as back contact are used respectively. In this paper, the carrier concentration changes, thicknesses effects, temperature stability and effect of two buffer layers of Zinc Stannate (Zn 2 SnO 4 ) and Zinc Oxide (ZnO) on the CdTe solar cell output performance are investigated to obtain an optimum thin film structure of CdTe solar cell. This study aims to obtain the thickness of 1 μm for CdTe absorber layer. The conversion efficiency of the optimized structure of CdTe thin film solar cell (SnO 2 /CdS/CdTe/Mo) is up to 21.313% (V OC = 0.756 V, J SC = 34.282 mA/cm2 and FF = 0.822) with a thickness of 1.2 μm. Obviously, this structure is cost-efficient due to its thickness. Furthermore, temperature coefficient of the final proposed structure (ZnO, Zn 2 SnO 4 /SnO 2 /CdS/CdTe/Mo) is less than 0.031% /°K which shows a well stability at higher operating temperature of the proposed CdTe thin film solar cell. Therefore, this CdS/CdTe structure can be a prospect of thin film solar cell with high efficiency.