Thin Film Solar Cell Modeling, Numerical Simulation and Performance Optimization Based on CdS with CdTe/CdxZn1-xTe Solar Cell as a Function of Cell Thickness

Abstract

This paper presents the comparison, modeling, numerical simulation and optimization of thin film solar cell based on n-CdS/p-CdTe n-CdS/p-CdZnTe and n-CdS/p-CdTe/p-CdZnTe material, which is being a promising photovoltaic material. Thin-film technologies help in reducing the thickness of active layer material in a cell. CdTe is a very chemically stable and robust material. The simulation results show a reasonable agreement with the experimental data, indicating the reliability of simulation results. The optimum band gap of CdTe is well suited according to the Schockley-Queisser limit and has capability to deliver very high efficiencies as a single junction device of more than 32%, with an open circuit voltage around 1 V and a short circuit current density exceeding 30 mA/cm². To achieve the highest efficiency, the thickness of CdTe and CdS was changed separately to control the improvement of cell efficiency and more than 23% efficiency was achieved. The CdS window layer was varied from 10 nm to 60nm and the thickness of CdTe absorber layer was varied from 300 nm to 1000 nm. The numerical simulation was done using TCAD tool. The highest conversion efficiency obtained was 23.75% with open circuit voltage as 1007.68 mV short circuit current density 37.40 mA/cm² with thicknesses 10 nm CdZnTe, 500 nm CdTe and 60 nm of CdS.