Original research articleDesign prospects of cadmium telluride/silicon (CdTe/Si) tandem solar cells from numerical simulation

Tandem or multi-junction structures have been utilized to enhance the performance of existing solar cell to achieve higher efficiency in thin film solar cells with the least material usage. In this paper, silicon (Si) has been used as the multi junction partner with the standard CdTe solar cell (n-SnO2/n-CdS/p-CdTe/Al) structure to investigate the efficiency and stability. Photovoltaic properties of CdTe/Si tandem solar cell with the configuration of n-SnO2/n-CdS/p-CdTe/p+-CdTe/n+-Si/n-Si/p-Si/p+-Si/Al have been studied by Analysis of Microelectronic and Photonic Structure (AMPS-1D) simulation software. This modified structure has been investigated by adding tunnel junction, which consists of highly doped p-CdTe and n-Si with the variation of simulation parameters such as layer thickness, carrier concentration and operating temperature. Enhanced photovoltaic effects have been observed by optimizing the layer thickness of p-CdTe, n-Si, p-Si and carrier concentration of p-CdTe. From the simulation result, the best efficiency of 28.457% has been achieved for CdTe/Si tandem structure with Voc = 1.15 V, Jsc = 27.612 mA/cm2, FF = 0.894 as compared with the baseline CdTe solar cell efficiency of 19.701%.