稀土硫族钙钛矿：一类用于光电子应用的极具潜力的材料
Rare-earth chalcogenide perovskites: A promising class of materials for optoelectronic applications
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中文总结 AI 辅助
该研究采用第一性原理方法探究稀土硫族钙钛矿ABX₃的结构、光电子、激子及极化子特性，发现其兼具多种优异性能，有望用于下一代光电子器件。
中文摘要 AI 辅助
稀土硫族钙钛矿因具有无毒组成、优异的相稳定性和出色的光电子性能，在光电子应用领域受到了广泛关注。然而，由于精确理论处理的计算成本过高，其激子和极化子特性仍在很大程度上未被探究。在本研究中，我们采用最先进的密度泛函理论结合G₀W₀框架下的多体微扰理论及贝特-萨尔彼得方程（BSE），对一系列III-III型稀土硫族钙钛矿ABX₃（A=Y、La；B=Sc、Y；X=S、Se）的激子动力学、极化子效应，以及它们的结构稳定性和光电子性能展开了全面的第一性原理研究。所有被研究的化合物均满足动力学和力学稳定性判据，其准粒子带隙处于2.75-4.47 eV范围内；BSE计算显示，它们具有覆盖可见光至紫外区域的强光学吸收特性。计算得到的激子特性表明，这些材料具有中等至较大的激子结合能（0.148-0.517 eV）、适度定域的激子，以及强电子-空穴波函数重叠，这预示着良好的辐射复合特性和增强的光-物质相互作用。此外，基于弗罗利希模型的分析表明，这些材料具有中等至强的载流子-声子耦合，且电子-声子相互作用通常强于空穴-声子相互作用。总体而言，稀土硫族钙钛矿ABX₃兼具结构稳定性、可调的光电子性能、显著的激子效应和良好的极化子输运特性，使其成为下一代光电子器件（包括发光器件和光电探测器）的极具潜力的无铅材料。
英文摘要
Rare-earth chalcogenide perovskites have attracted significant attention for optoelectronic applications due to their nontoxic composition, robust phase stability, and excellent optoelectronic properties. However, their excitonic and polaronic properties remain largely unexplored due to the high computational cost of accurate theoretical treatments. In this work, we present a comprehensive first-principles investigation of excitonic dynamics and polaronic effects in a series of III-III rare-earth chalcogenide perovskites ABX$_{3}$ (A = Y, La; B = Sc, Y; X = S, Se), along with their structural stability and optoelectronic properties, using state-of-the-art density functional theory in conjunction with many-body perturbation theory within the G$_{0}$W$_{0}$ and Bethe-Salpeter equation (BSE) frameworks. All investigated compounds satisfy the dynamical and mechanical stability criteria. They exhibit quasiparticle band gaps in the range of 2.75$-$4.47 eV, and the BSE calculations reveal strong optical absorption spanning the visible to ultraviolet regions. The computed excitonic properties indicate intermediate-to-large exciton binding energies (0.148$-$0.517 eV), moderately localized excitons, and strong electron-hole wavefunction overlap, indicative of favorable radiative recombination characteristics and enhanced light-matter interaction. Furthermore, analysis based on the Fröhlich model demonstrates intermediate-to-strong carrier-phonon coupling, with electron-phonon interactions generally stronger than hole-phonon interactions. Overall, rare-earth chalcogenide perovskites ABX$_{3}$ exhibit a compelling combination of structural stability, tunable optoelectronic properties, pronounced excitonic effects, and favorable polaronic transport, positioning them as promising lead-free materials for next-generation optoelectronic devices, including light-emitting devices and photodetectors.
