Crystal growth, electronic structure and optical properties of BaZrS<sub>3</sub> and its Ruddlesden-Popper phases
ORAL
Abstract
Transition metal perovskite chalcogenides (TMPCs) are a new class of semiconductors with d0 configuration. The less electronegative chalcogen, compared to oxides, lead to reduced band gap, more covalent bonding, and other interesting physical properties. We report the crystal growth and physical property study of BaZrS3, Ba3Zr2S7 and Ba2ZrS4. Photoluminescence (PL) measurements were performed to study the optical properties. Scanning Kelvin probe microscopy and Hall measurements were carried out to study the electronic structure and transport phenomena. Optical band gap of 1.82, 1.28 and 1.33 eV for BaZrS3, Ba3Zr2S7, and Ba2ZrS4, respectively, were extracted from PL. Such band gap evolution trend is different from that observed in oxide and halide counterparts. Potential effect of octahedra tilting and Zr-S covalent bonding in determining the electronic structure were explored. External luminescence efficiency up to 0.2% and effective minority carrier lifetime longer than 65 ns in Ba3Zr2S7 was also obtained by quantitative and time-resolved PL, respectively.
Reference:
1. S. Niu, et al. Chem. Mater. 30(15), 4882 (2018).
2. S. Niu, et al. Nat. Photon. 12(7), 392 (2018).
3. S. Niu, et al. Adv. Mater. 29(9), 1604733 (2017).
Reference:
1. S. Niu, et al. Chem. Mater. 30(15), 4882 (2018).
2. S. Niu, et al. Nat. Photon. 12(7), 392 (2018).
3. S. Niu, et al. Adv. Mater. 29(9), 1604733 (2017).
*Link Energy Fellowship, APS FIP Distinguished Student program
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Presenters
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Shanyuan Niu
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California
- Department of Chemical Engineering and Materials Science, University of Southern California