HIGH EFFICIENCY CIGS SOLAR CELL WITH Zn_xCd_1-xS WINDOW LAYER

This work conduct the numerical modeling of Zn_xCd_1-xS/CIGS solar cells using the AMPS-1D software aiming to boost the efficiency and thermal stability of the solar cells. The substitute of typical cadmium sulfide (CdS) window/buffer layer with ternary ZnxCd1-xS window layer in Cu (In, Ga)Se2 (CIGS) solar cells have been analyzed by AMPS-1D. The prospects of zinc (Zn) incorporation in CdS as window layer for CIGS absorber layer is investigated here. The main goal of this work is to enhance the performance of thin film ZnxCd1-xS/CIGS solar cells with submicron absorber, which could lead to significant reduction of production cost and wider commercial usage. Analysis shows that 0.5-0.6 μm CIGS absorber layer gives good performance with suitable back surface field (BSF). The specific BSF material selected to be investigated here is As2Te3. The best calculated ultrathin Zn_xCd_1-xS/CIGS solar cell with suggested value of ‘x’ from the simulation result with a 100 nm of As2Te3 BSF layer should have an absorber layer thickness of 0.6 μm (efficiency 31.096%), higher stability in most extents, as it was found that the cells have relatively lower negative temperature coefficient (TC)with a TC of -0.031%/°C in the operating temperature range 45°C to 100°C and efficiency remains almost unchanged from 25°C to 45°C.