Prospective efficiency boosting of full-inorganic single-junction Sb2(S, Se)3 solar cell

Abstract

Antimony selenosulfide, Sb2(S, Se)3, is regarded as an appropriate absorber to be utilized in terrestrial single junction solar cell applications thanks to the tunability of its bandgap energy which could be adjusted around 1.3 eV. To enhance the power conversion efficiency (PCE) of Sb2(S, Se)3-based single junction solar cell, we propose some design recommendations by using device simulation. First, in order to validate the simulation model, a calibration step is accomplished by comparing the numerical simulation results with those of a fabricated cell structure consisting of Au/Sb2(S, Se)3/CdS/ITO. The designed cell is formed without an organic hole transport layer (HTL) which, generally, harmfully affects the cell by causing stability issues. Next, we investigate the impact of the conduction band offset (CBO) between the electron transport layer (ETL) and the Sb2(S, Se)3 absorber utilizing the bandgap tunable material Cd1-xZnxS to achieve the optimum CBO. Various key design parameters for the presented cell such as the back contact work function as well as absorber thickness and doping concentration are also inspected. It is found that the most crucial parameter that affects the cell performance is the CBO which could be adjusted by modifying the Zn fraction in the ternary compound Cd1-xZnxS. Moreover, a study on the impact of the interface and bulk defects on device performance is carried out. The simulations, conducted in this study, are accomplished by SCAPS-1D simulator at 300 K temperature and under AM1.5G illumination.