Abstract
Quaternary halide double perovskites exhibit a range of electronic properties,making them candidates for a variety of applications,notably in optoelectronics.The determination of the band gap of these materials has proved difficult and large discrepancies are found in results reported in the literature.In this work,we use first-principles methods to study the electronic structure of cesium chloride double perovskites Cs2B'B"Cl6,with B'= Ag,Na and B"= Bi,In.We employ the DFT-1/2 approximate quasiparticle method to determine the electronic structure of these materials.This approach is an accurate and computationally efficient alternative to more expensive techniques,like hybrid functionals and GW quasiparticle calculations,opening an avenue to study more complex systems,as heterostructures,interfaces,and defects.
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