Potential lead-free small band gap halide double perovskites Cs2CuMCl6 (M\u2009=\u2009Sb, Bi) for green technology

Muskan Nabi,Dinesh C Gupta

doi:10.1038/s41598-021-92443-1

Abstract

Explorations of stable lead-free perovskites have currently achieved substantial interest to overcome the instability and avoid toxicity related issue faced with the lead-based perovskites. In this study, we have comprehensively studied the stability, nature and origin of electronic, transport and optical properties of inorganic halide double perovskites, which could provide a better understanding of their possible potential applications. The density functional theory is used to investigate the different physical properties of these materials. The stability of these cubic materials is validated by optimizing the structure, tolerance factor, mechanical stability test. The materials are small band gap semiconductors with outshining optoelectronic performance. Due to high optical absorption, high conductivity and low reflectivity they have great potential to be used for optoelectronic application purpose. Because of small band gap we have also investigated the variation of various transport parameters with chemical potential. The semiconducting nature of materials results in ZT close to unity predicting its excellent application in thermoelectric technology.

Highlights

Explorations of stable lead-free perovskites have currently achieved substantial interest to overcome the instability and avoid toxicity related issue faced with the lead-based perovskites
There is a sustained research interest toward alternative photovoltaic (PV) materials produced with cost-competitive, facile, and environmentally friendly technologies. In this field perovskite solar cells have gained much progress during the last few decades increasing the efficiency from 3.8% in 2009 to 22.7% in 2017 at the lab-scale[1,2,3,4,5]
There are many issues associated with the commercialization of lead based solar cells instability and toxicity[6,7]

Summary

Introduction

Explorations of stable lead-free perovskites have currently achieved substantial interest to overcome the instability and avoid toxicity related issue faced with the lead-based perovskites. There is a sustained research interest toward alternative photovoltaic (PV) materials produced with cost-competitive, facile, and environmentally friendly technologies In this field perovskite solar cells have gained much progress during the last few decades increasing the efficiency from 3.8% in 2009 to 22.7% in 2017 at the lab-scale[1,2,3,4,5]. Despite ultra-low thermal conductivity arising because of occupation of cations in the octahedral structure along with high charge mobility, it is quite surprising that these halide double perovskites have been mostly studied for optoelectronic applications. Motivated by their small band gap and unmatchable desirable properties, we have tried to explore these two materials for optoelectronic application and extended our study to unravel their thermoelectric properties which they justify

Methods

Findings

Conclusion