Synthesis and complex impedance analysis of nano cubic CH3NH3SnI3 perovskite for the development of optoelectronic lead-free Schottky diode

Abstract

The synthesis of a lead-free tin-based perovskite material is a crucial step toward developing a sustainable energy device. However, the oxidation of Sn2+ to Sn4+ during synthesis in an open atmosphere is the basic synthetic problem in tin-based perovskites. In this study, a modified technique for nanoparticle synthesis was applied to submerge the oxidation issues and synthesised nano cubic tin-based hybrid CH3NH3SnI3 perovskite in the glove box in an inert environment (N2) to make the Schottky device. The crystallinity of the synthesised perovskite sample was confirmed by PXRD. The structural parameters such as crystalline size (D), dislocation density (δ), strain (ε), and the lattice parameter were calculated from the XRD pattern and were found to be 62.90 nm, 2.52 × 1014 nm−2, 6.12 × 10−3 lin−2/m−4, and 6.23951 Å, respectively. The material was characterised by UV–Vis. spectroscopy, TGA, FESEM, and EDX measurements. The frequency-dependent transport properties of this perovskite sample were investigated using complex impedance spectroscopy (CIS) in the frequency range of 4 Hz–8 MHz. The conductivity relaxation time, DC conductivity, and AC conductivity were calculated as 6.45 × 10−5 s, 2.01 × 10−6 S/m, and 6.98 × 10−4 S/m, respectively. A Schottky device was fabricated using this perovskite. Excellent performance of this device was observed from its electrical characterization in terms of conductivity both in the dark (1.04 × 10−6 S/m) and light (1.96 × 10−6 S/m) conditions. So, this work will be very beneficial to the further development of the lead-free CH3NH3SnI3 perovskite and its subsequent electrical applications.