@article{f4de115560274455a2147efef12b54e0,
title = "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",
abstract = "Chalcogenides in perovskite and the related layered Ruddlesden-Popper crystal structures (chalcogenide perovskites for 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 perovskite BaZrS3 and Ruddlesden-Popper Ba3Zr2S7. 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 in Ba3Zr2S7 and 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.",
author = "Kevin Ye and Koocher, {Nathan Z.} and Stephen Filippone and Shanyuan Niu and Boyang Zhao and Matthew Yeung and Sharon Bone and Robinson, {Adam J.} and Patrick Vora and Andr{\'e} Schleife and Long Ju and Alexey Boubnov and Rondinelli, {James M.} and Jayakanth Ravichandran and R. Jaramillo",
note = "Funding Information: We acknowledge support from the National Science Foundation (NSF) under Grant No. 1751736, “CAREER: Fundamentals of Complex Chalcogenide Electronic Materials.” A portion of this project was funded by the Skolkovo Institute of Science and Technology as part of the MIT-Skoltech Next Generation Program. K.Y. and M.Y. acknowledge support by the NSF Graduate Research Fellowship, Grant No. 1745302. S.N., B.Z., and J.R. acknowledge the support from the Army Research Office under Awards No. W911NF-19-1-0137 and No. W911NF-21-0327 and the University of Southern California Provost New Strategic Directions for Research Award. A.S. acknowledges support by the NSF under Grant No. DMR-1555153. P.M.V. and A.J.R. acknowledge support from the NSF under Grant No. 1847782, “CAREER: Proximity Effects in van der Waals Heterostructures.” N.Z.K. and J.M.R. were supported by NSF Grant No. DMR-2011208. Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515. A.B. acknowledges support by the state of Baden-W{\"u}rttemberg through bwHPC and the German Research Foundation through Grant No. INST 40/575-1 FUGG (JUSTUS 2 cluster). DFT calculations used the Extreme Science and Engineering Discovery Environment, which is supported by the NSF under Grant No. ACI-1548562 and the National Energy Research Scientific Computing Center, a U.S. DOE Office of Science User Facility located at Lawrence Berkeley National Laboratory, operated under Contract No. DE-AC02-05CH11231. Publisher Copyright: {\textcopyright} 2022 American Physical Society.",
year = "2022",
month = may,
day = "15",
doi = "10.1103/PhysRevB.105.195203",
language = "English (US)",
volume = "105",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "19",
}