International Journal of Energy Research, Vol.45, No.5, 7222-7234, 2021
Small-band gap halide double perovskite for optoelectronic properties
The long-term instability and the existence of toxic lead have hindered the commercialization of photovoltaic devices. Perovskites offer a multitude of crystallographic configurations and substituents that portend the promise of enhanced device performance, while resolving concerns of stability and toxicity. During past few years, lead free perovskites have emerged the most promising photovoltaic materials. Herein, we reported new lead-free organic perovskites by first principle calculation with possible application in optoelectronic and spintronic devices. The new halide double perovskites Cs2GeVX6 (X = Cl, Br, I) has a smallest band gap ranging from 2 to 3 eV suitable for optoelectronic application in visible as well as UV region. Band profile reveals semiconducting nature of these materials with high values of magnetic moment. Stability of these alloys is determined by calculating the elastic constants. These materials owe brilliant intrinsic properties because of large number of nearest neighboring magnetic ions and strong coupling between various d, s, p orbitals. Our finding will pave a way for future experimentalists for designing and tuning of new-type Pb-free halide perovskite for optoelectronic application.