Exploration HTL-Free all inorganic mixed halide perovskite solar cells: effects of 4-ADPA passivation

Abstract

The incredible PV performance of thin-film perovskite solar cells has garnered the attention of researchers. Mixed halide perovskite outweighs pure halide perovskite in its ability to optimize PV performance while performing material composition engineering. All inorganic mixed halide (AIMH) perovskite CsPbI2Br has shown stable performance against thermal variations. This study mainly highlights the performance of HTL (Hole transport layer) free, passivated solar cell structure with utilization of the SCAPS-1D simulator. The inclusion of passivation layer 4-ADPA(4-aminodiphenylamine) between active layer CsPbI2Br and the end electrode mitigates the occurrence of charge carrier recombination. The thickness of passivation layer 4-ADPA is optimized for the range 100 nm – 1000 nm, and 100 nm is decided as the optimum width based on the evaluated PV performance of SnO2/CsPbI2Br/4-ADPA/anode. 4-ADPA layer with an optimum thickness of 100 nm, is embedded with a CsPbI2Br layer, and the performance of solar cell has been investigated under the collective impact of BDD (bulk defect density)/thickness of CsPbI2Br for the range (1012 cm-3 to 1018 cm-3)/(50 nm to 500 nm) respectively. Further, this study investigated the capacitance-voltage (C-V), Mott – Schottky (1/C2), and Nyquist plot (C-F) performance of solar cells under the influence of only BDD for two cell configurations (corresponding to maximum and minimum delivered PCE i.e., thickness/BDD is 200nm/1012 cm-3 and 500 nm/1018 cm-3 respectively). The highest 13.27% of PCE is extracted from HTL-free, 4-ADPA passivated all inorganic PSC, at 200nm/1012 cm-3 of thickness/BDD respectively. This technique encourages researchers to explore more cost-effective, HTL-free passivated solar cell structures.