Numerical modelling and optimization of CdS/CdTe solar cell with incorporation of Cu2O HT-EBL layer

In the recent years, use of CdTe thin-film as an absorber in solar cells has been augmented significantly due to high device efficiency, stability in the performance and cost effectiveness. In this work, CdTe solar cell has been investigated employing 2-dimensional numerical simulations using TCAD Silvaco-Atlas simulator. Initially, a reference structure of FTO/i-SnO2/CdS/CdTe solar cell was simulated based on experimental data for the validity of the simulation and the extent to which present results agree to the experimental data. To reduce the minority carrier recombination loss, a new structure is proposed by incorporation of the cuprous oxide (p-type Cu2O) layer at back-contact as a hole transport-electron blocking layer (HT-EBL). High performancehas been obtained by optimizing the cell parameters in terms of thickness, doping concentration and carrier lifetime. The efficiency of the structure is increased by 10.35% compared to the recent experimental results. Furthermore, the proposed structure consists of FTO/i-SnO2/CdS/CdTe/Cu2O presents the best conversion efficiency of 24.35%, short-circuit current density of 27.59 mA/cm2, open-circuit voltage of 1.03 V and fill-factor of 85.83%, under the air mass 1.5 global spectrum (AM1.5G).