Bismuth-induced band-tail states in GaAsBi probed by photoluminescence
Journal article, 2019
Band-tail states in semiconductors reflect the effects of material growth and/or treatment, affect the performance of optoelectronic applications, and are hence a well-concerned issue. Dilute-Bi GaAs is considered very competitive though the role of Bi is yet to be well clarified. We in this letter investigate the effect of Bi incorporation on the band-tail states in GaAs 1−x Bi x by excitation power- and magnetic field-dependent photoluminescence (PL) measurements at low temperatures. Three PL features are identified from a broad PL peak, which blue-shift monotonically with the increase in excitation power. None of the PL features correlate with single Bi-content free-exciton recombination, and band-tail filling rather than the donor-acceptor pair process is responsible for the power-induced blueshift. The density of band-tail states gets enhanced with the increase in the Bi incorporation level and affects the determination of Bi-induced bandgap reduction. The results indicate that joint analysis of excitation- and magneto-PL may serve as a good probe for band-tail states in semiconductors.
Author
Bing Yan
Shanghai Normal University
Chinese Academy of Sciences
X Chen
Chinese Academy of Sciences
Liangqing Zhu
East China Normal University
Chinese Academy of Sciences
W. W. Pan
Chinese Academy of Sciences
L Wang
Chinese Academy of Sciences
L. Yue
Chinese Academy of Sciences
Xiaolei Zhang
Chinese Academy of Sciences
Li Han
Chinese Academy of Sciences
Feng Liu
Shanghai Normal University
Shu Min Wang
Chalmers, Microtechnology and Nanoscience (MC2), Photonics
Chinese Academy of Sciences
J. Shao
Chinese Academy of Sciences
Applied Physics Letters
0003-6951 (ISSN) 1077-3118 (eISSN)
Vol. 114 5 052104Subject Categories
Atom and Molecular Physics and Optics
Other Physics Topics
Condensed Matter Physics
DOI
10.1063/1.5079266