Cuinse2 Solar Cells Efficiency Optimization

In the present paper calculation of CuInSe2(CIS)/CdS solar cell efficiency is presented. The influence of the thickness and the optical band gap of CdS and CIS layers on the solar cell performances are investigated. The thickness of CdS buffer layer, which is generally neglected is taken into account. The solar cells performances calculations are based on the calculation, by means of developed software written with Matlab, of photocurrent from the resolution of the well known three coupling equations: continuity equation for holes in the CdS (n-region) and for electrons in the CIS (p- region) and Poisson equation. The obtained results indicated that the solar cell efficiency can be improved by reducing the CdS thickness or by increasing the CIS thickness. The efficiency increasing rates are 0.01 %/ nm and 0.5 %/nm for CdS and CIS layer thickness respectively. The CdS layer alters the shorter wavelength of the solar spectrum, while the CIS layer alters the longer wavelength. CIS layer optical band gap is the most crucial parameter by comparison to the optical gap of CdS layer.