Study of CIGS Absorber Thickness and Gradient Bandgap effect on Device Performance

This paper uses wxAMPS software to carry out simulation calculation about the influence of parameter changes on device performance of copper indium gallium selenide (CIGS) thin film solar cell, with structure of soda lime glass substrate/Mo thin film bottom electrode/CIGS absorber layer/CdS buffer layer/i-ZnO thin film high resistance layer/AZO thin film transparent conductive layer. With different absorption layer thickness, we simulate the gradient distribution of the band gap of the CIGS thin-film absorption layer in the solar cell. By calculating the device efficiency with the minimum band gap at different positions, we have found the most suitable position of the minimum band gap for this model is near the front absorption layer and the device efficiency with absorption layer thickness 1.5um is similar to that of 2um, which means the thin absorption layer of the solution method can be effective.