Morphological improvement of a novel & non-toxic double perovskite MA2NaBiCl6 by thermal annealing treatment: Enhanced the PCE of solar cell device

In perovskite solar cells, annealing time and temperature are crucial parameters to obtain high quality film crystallization, desired morphology, and texture. Annealing enhances charge-carrier transport and minimizes non-radiative defects, resulting in improved power conversion efficiency (PCE). Firstly, we have synthesized a novel and hybrid halide double perovskites (DP) material MA 2 NaBiCl 6 using hydrothermal and we have done material characterizations. We have fabricated solar cell using as-synthesized DP as a absorber material, ZnO as electron transport layer and Cu 2 O as hole transport layer and performance parameters was calculated. Furthermore, to enhance the device performance, we have annealed it at different temperature varying from 50 to 225 °C and analyzed improvements in material’s morphology and device performance. Also, the annealing time (30 s–5 min) was varied at optimum annealing temperature. The optimized annealing temperature and time is 200 °C and 2 min respectively on which we achieved 3.49% PCE from the RT efficiency 1.671%. Graphical abstract