First-Principles Study of Electronic Properties of Cesium Chloride Double Perovskites Using a DFT-1/2 Approach

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 Cs 2 B′B″Cl 6 , 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.

Self-energy correction and numerical simulation for efficient lead-free double perovskite solar cells

“…Due to the self-interaction effect in the occupied states and the absence of the derivative discontinuity Δ xc , 43 the band gap is usually underestimated. To address this issue, the DFT-1/2 correction is applied to accurately determine the band gap.…”

“…And the binding energy of Cs 2 CuBiBr 6 is smaller than that of Cs 2 AgBiBr 6 , which proves that Cs 2 CuBiBr 6 is easier to form. Due to the self-interaction effect in the occupied states and the absence of the derivative discontinuity D xc , 43 the band gap is usually underestimated. To address this issue, the DFT-1/2 correction is applied to accurately determine the band gap.…”

Synthesis and Optimization of Cs2B′B″X6 Double Perovskite for Efficient and Sustainable Solar Cells

“…Therefore, one way to adjust the band gap is that, because the material structure belongs to the cubic crystal system, the original configuration of the material will be changed under the action of pressure or temperature, resulting in a change in the band gap. Another method is to change the atomic arrangement for structural transformation, by adding dopants to the double perovskite material to change the band gap [ 85 , 86 , 87 ]. This section will focus on the methods of structural transition and functional doping to adjust the band gap.…”

A first-principles study of MgSnN2 films using a DFT-1/2 approach

“…However, the SCAN functional is not suitable for MgSnN 2 [17]. We noticed that, a DFT-1/2 treatment has been developed and proven to be useful for semiconductors since it takes into account the self-energy potential of specific atoms [50][51][52][53][54][55]. To ensure the accuracy of the calculations, we have supplied a comparison of different functionals for several II-IV-N 2 nitrides with experimental measurements, as shown in figure 2.…”