Computational study of the fundamental properties of Zr-based chalcogenide perovskites for optoelectronics

Abstract

Chalcogenide perovskites have recently attracted enormous attention since they show promising optoelectronic properties and high stability for photovoltaic applications. Herein, the relative stability and photoactive properties of chalcogenide perovskites AZrX3...

Discovery of Rb-based auric–aurous halide perovskites as promising narrow bandgap semiconductors for energy conversion applications

“…This trend has been observed in the bandgap calculations of other AAHPs, 18,19,22 confirming the reliability of our computational results. Despite prior reports 48 suggesting a direct bandgap for Rb 2 Au 2 I 6 , our single-crystal-based calculations demonstrate an indirect bandgap for this compound with the conduction band minimum (CBM) at G and the valence band maximum (VBM) at Y (Fig. 3a).…”

How the Temperature and Composition Govern the Structure and Band Gap of Zr-Based Chalcogenide Perovskites: Insights from ML Accelerated AIMD

“…From the data presented in Figure 8 , we conclude that the calculated band-gap values fall within the optimal range 68 of single-junction photovoltaic devices for all compositions of selenides across all temperatures. While the band gaps of CaZrS 3 and SrZrS 3 are slightly above the desired range, the E g value for BaZrS 3 moves into the range above 400 K. Since BaZrX 3 (X = S, Se) is expected to show early phase transitions to the ideal cubic phase (600–900 K), we anticipate that the thermal band gaps could be eventually tuned to the optimal photovoltaic range by exploring the mixed BaZrS 3– x Se x compositions, as also proposed by Liu et al 21 …”

“…This is also the most important factor affecting the magnitude of their band gap. Of course, the structural distortions can also be achieved by other means, e.g., via partial substitutions of cations and/or anions by atoms of different sizes, which we plan to investigate in our future work. Also, the CP materials are known to exist in several competing phases, such as the orthorhombic NH 4 CdCl 3 -type and hexagonal structure. , A correct ranking of the relative stability of the DP phase with respect to these alternative structures is a pertinent and challenging problem, requiring accurate free-energy calculations at a suitable level of theory to accurately predict energy differences that are sometimes extremely small.…”

“…This is also the most important factor affecting the magnitude of their band gap. Of course, the structural distortions can also be achieved by other means, e.g., via partial substitutions of cations and/or anions by atoms of different sizes, 21 which we plan to investigate in our future work. Also, the CP materials are known to exist in several competing phases, such as the orthorhombic NH 4 CdCl 3 -type and hexagonal structure.…”

“…Meng et al 20 suggested that compositions such as BaZrSe 3 and BaZr 1– x Ti x S 3 have an optimal band gap for use in single-junction solar cell, with a theoretical maximum efficiency of up to 30%. Liu et al 21 reported theoretical investigations on AZrX 3 (A = Ca, Sr, Ba; X = S, Se) at 0 K, suggesting selenide compositions as promising candidates for photovoltaic applications based on their stability, mechanical, electronic, and optical properties. However, such compositions have not yet been prepared experimentally.…”