Lead-Free Perovskite Narrow-Bandgap Oxide Semiconductors of Rare-Earth Manganates

Lei Chen; Guifang Zheng; Gang Yao; Pingjuan Zhang; Shangkai Dai; Yang Jiang; Heqin Li; Binbin Yu; Haiyong Ni; Shizhong Wei

doi:10.1021/acsomega.0c00138

Lead-Free Perovskite Narrow-Bandgap Oxide Semiconductors of Rare-Earth Manganates

ACS Omega. 2020 Mar 24;5(15):8766-8776. doi: 10.1021/acsomega.0c00138. eCollection 2020 Apr 21.

Authors

Lei Chen^{1

2}, Guifang Zheng¹, Gang Yao¹, Pingjuan Zhang^{1

3}, Shangkai Dai¹, Yang Jiang¹, Heqin Li¹, Binbin Yu⁴, Haiyong Ni⁵, Shizhong Wei⁶

Affiliations

¹ School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China.
² Engineering Research Center of High Performance Copper Alloy Materials and Processing, Ministry of Education, Hefei University of Technology, Hefei 230009, China.
³ College of Electrical and Electronic Engineering, Anhui Science and Technology University, Bengbu 233030, China.
⁴ SUSTech Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China.
⁵ Guangdong Province Key Laboratory of Rare Earth Development and Application, Guangdong Research Institute of Rare Metals, Guangdong Academy of Sciences, Guangzhou 510651, China.
⁶ National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials, Henan University of Science and Technology, Luoyang 471003, China.

Abstract

Tremendous success has been achieved in photovoltaic (PV) applications, but PV-generated electricity still cannot compete with traditional power in terms of price. Chemically stable and nontoxic all-oxide solar cells made from earth-abundant resources fulfill the requirements for low-cost manufacturing under ambient conditions and thus are promising as the next-generation approach to solar cells. However, the main obstacles to developing all-oxide solar cells are the spectral absorbers. Besides photovoltaics, novel chemically stable, nontoxic, and earth-abundant narrow-bandgap semiconductors are desired for photochemical applications in photodetectors, photoelectrodes, or photocatalysts. Herein, were report novel lead-free perovskite narrow-bandgap rare-earth semiconductors, YMnO₃, HoMnO₃, ErMnO₃, and YbMnO₃, which were identified by screening a family of perovskite rare-earth manganates, RMnO₃ (R = Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, and Yb). The sharp edge observed in their absorption spectra indicates the existence of band gaps, further confirmed with laser Raman fluorescence spectra. Good periodic on-off photoelectronic response was observed in 8 of the 12 members (i.e., R = La, Pr, Nd, Sm, Gd, Tb, Dy, and Yb). Among them, YbMnO₃ is approved as an n-type semiconductor with a direct band gap near 1.35 eV, whose theoretical Shockley-Queisser efficiency is approximately 33.7% for single-p-n-junction solar cells. This work sheds light on exploring stable oxide semiconductors with a narrow band gap for future applications.