Low-energy electronic structure of perovskite and Ruddlesden-Popper semiconductors in the Ba-Zr-S system probed by bond-selective polarized x-ray absorption spectroscopy, infrared reflectivity, and Raman scattering
Low-energy electronic structure of perovskite and Ruddlesden-Popper semiconductors in the Ba-Zr-S system probed by bond-selective polarized x-ray absorption spectroscopy, infrared reflectivity, and Raman scattering
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DOI：
10.1103/physrevb.105.195203
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发表时间：
2022-05
影响因子：
3.7
通讯作者：
Kevin Ye;Nathan Z. Koocher;Stephen Filippone;Shanyuan Niu;Boyang Zhao;M. Yeung;S. Bone;Adam J. Robinson;P. Vora;A. Schleife;Long Ju;A. Boubnov;J. Rondinelli;J. Ravichandran;R. Jaramillo
中科院分区：
文献类型：
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作者：
Kevin Ye;Nathan Z. Koocher;Stephen Filippone;Shanyuan Niu;Boyang Zhao;M. Yeung;S. Bone;Adam J. Robinson;P. Vora;A. Schleife;Long Ju;A. Boubnov;J. Rondinelli;J. Ravichandran;R. Jaramillo
钙钛矿中的硫系化合物和相关的层状Ruddlesden-Popper晶体结构（简称硫系钙钛矿）是一个令人兴奋的半导体家族，但实验研究很少。硫系钙钛矿与氧化物和卤化物钙钛矿等离子化合物具有相同的晶体结构和一些物理性质，但与这些研究较多的钙钛矿相比，负责半导体行为的金属-硫键的共价性更强。本文采用互补的实验和理论方法，研究了混合离子-共价Zr-S键如何支持钙钛矿和Ruddlesden-Popper的电子结构和物理性质。我们应用理论方法将实验测量的x射线吸收光谱（XAS）的特征分配到特定的轨道跃迁，从而能够对单晶样品上测量的角度依赖的偏振XAS数据进行清晰的物理解释，并从原子的角度看待促进电荷传输的共价键网络。偏振拉曼测量确定了晶体各向异性的特征，并使这种材料的模式对称性的首次分配成为可能。红外反射率揭示了电子输运特性，这预示着硫系钙钛矿在光电和能量转换技术中的应用。
Chalcogenides in perovskite and the related layered Ruddlesden-Popper crystal structures (chalcogenide perovskitesfor brevity) are an exciting family of semiconductors but remain experimentally little studied. Chalcogenide perovskites share crystal structures and some physical properties with ionic compounds such as oxide and halide perovskites, but the metal-chalcogen bonds responsible for semiconducting behavior are substantially more covalent than in these more-studied perovskites. Here, we use complementary experimental and theoretical methods to study how the mixed ionic-covalent Zr-S bonds support the electronic structure and physical properties of perovskiteand Ruddlesden-Popper. We apply theoretical methods to assign features of experimentally measured x-ray absorption spectroscopy (XAS) to particular orbital transitions, enabling a clear physical interpretation of angle-dependent, polarized XAS data measured on single-crystal samples, and an atomistic view of the covalent bonding network that facilitates charge transport. Polarized Raman measurements identify signatures of crystalline anisotropy inand enable the first assignments of mode symmetry in this material. Infrared reflectivity reveals electronic transport properties that augur well for the use of chalcogenide perovskites in optoelectronic and energy-conversion technologies.