Room temperature synthesis and experimental study of novel double perovskite MA2KBiCl6 for photovoltaic application

Abstract

Despite the increasing flexibility of lead (Pb) based single perovskites for optical applications, the issue of stability and Pb toxicity is a major concern for realizing stable and durable devices. To overcome these drawbacks, it is very important to synthesize new, stable and non-toxic perovskite materials. In this work, we have synthesized and characterized a novel, stable, and lead-free organic-inorganic hybrid halide-based double perovskite (DP) material MA₂KBiCl₆ for the first time by facile one-step hydrothermal method. The structural characteristic of MA₂KBiCl₆ is observed at room temperature by the X-ray diffraction (XRD) technique which confirms the phase formation and is in agreement with the reference data. Furthermore, photoluminescence (PL) spectroscopy of synthesized material was performed at room temperature (300K) to observe its optical characteristics. An excellent photoluminescence phenomenon has been observed in the material due to band-to-band transition as well as phonon-assisted carrier recombination. To see the surface morphology we have done the scanning electron microscopy (SEM) at room temperature which indicates the good crystalline behaviour of the synthesized material. Also, MA₂KBiCl₆ DP exhibit promising absorption phenomena having a direct and indirect bandgap of 3.125 eV and 2.750 eV respectively. Moreover, the transmittance phenomenon has been observed from the Fourier transform infrared spectroscopy (FTIR). This novel finding on the non-toxic double perovskite material MA₂KBiCl₆ has opened up opportunities for sustainable development of various double perovskite materials for photovoltaic utility.