Numerical Simulation of CZTSe Based Solar Cells Using Different Back Surface Field Layers: Improvement and Comparison

• Published in: Journal of electronic materials 2021-04, Vol.50 (4), p.2021-2033
• Main Authors: El Otmani, Rkia, El Manouni, Ahmed, Al Maggoussi, Abdelmajid
• Format: Article
• Language: English
• Subjects: Cadmium sulfide; Characterization and Evaluation of Materials; Chemistry and Materials Science; Circuits; Copper zinc tin selenide; Copper zinc tin sulfide; Doppler effect; Electronics and Microelectronics; Energy conversion efficiency; Instrumentation; Materials Science; Mathematical models; Open circuit voltage; Optical and Electronic Materials; Original Research Article; Parameters; Photovoltaic cells; Quantum efficiency; Red shift; Short circuit currents; Solar cells; Solid State Physics; Thickness; Thin films; Zinc oxide
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-020-08712-8

This work reports on a numerical modeling of Cu 2 ZnSnSe 4 (CZTSe) thin film based solar cells using Solar Cell Capacitance Simulator (SCAPS). First, a conventional CZTSe/CdS/ZnO solar cell structure has been proposed and optimized. The optimal output parameters (power conversion efficiency PCE = 24.50%, short circuit current density J sc  = 47.732 mA/cm 2 , fill factor FF = 80.478% and open circuit voltage V oc  = 0.639 V) have been obtained for ZnO, CdS and CZTSe layer thicknesses closed to 0.02 μm, 0.02 μm and 1.5 μm, respectively. Next, to improve on the conventional solar cell performance, three cell structures with different highly P-doped materials as back surface field (BSF) layers, such as P + -CZTSe, P + -Cu 2 O and P + -CZTS, have been proposed and optimized. In comparison to the conventional cell, devices with BSF layer have shown improvements of all the photovoltaic parameters. The CZTS/CZTSe/CdS/ZnO device has provided the highest performance (PCE = 25.83%, J sc  = 51.04 mA/cm 2 , FF = 78.14% and V oc  = 0.646 V) for ZnO, CdS, CZTSe and P + -CZTS thicknesses closed to 0.02 μm, 0.02 μm, 1.5 μm and 0.4 µm, respectively. Additionally, the generation rate is no affected by the BSF layer; however, the recombination rate has decreased in the bulk and back surface of the CZTSe absorber. Finally, the insertion of the BSF layer has caused an increase of external quantum efficiency (EQE) up to 94.5% and a slight red shift of absorption in the long-wavelength region near the band edge.