Open AccessLanthanum and strontium modified bismuth ferrite based perovskites with ultra-narrow band gaps
Author(s) -
Huanpo Ning,
Jian Yu
Publication year - 2020
Publication title -
materials research express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 35
ISSN - 2053-1591
DOI - 10.1088/2053-1591/abc376
Subject(s) - materials science , band gap , perovskite (structure) , lanthanum , strontium , x ray photoelectron spectroscopy , analytical chemistry (journal) , ultraviolet , infrared , optoelectronics , inorganic chemistry , crystallography , optics , nuclear magnetic resonance , chemistry , physics , organic chemistry , chromatography
The wide optical band gaps of ferroelectric perovskite oxides have restricted their light absorbing capacities in the photovoltaic devices. In this work, an ultra-narrow band gap E g and wide optical absorption across the ultraviolet-visible-infrared sunlight spectrum was achieved in lanthanum and strontium atoms modified Bi(Fe, Mn)O 3 perovskites by chemical substitution and defect engineering. XRD results show that the A and B site co-substituted samples are single phase. The XPS characterizations indicate the Fe ions are in the trivalent state for all the samples. The LM6 and SM6 samples exhibit an ultra-narrow band gap about 1.26 eV and 1.06 eV, respectively. The reduced E g was due to the defect states produced within the band gap, acting as a scaffold to give electrons to Fe 3d states and receive the electrons from O 2p states. Based on this research, these chemically modified BFO based perovskite could potentially extend its sunlight absorption deep into the infrared region.