Photoluminescence fatigue and inhomogeneous line broadening in semi-insulating Tl6SeI4 single crystals

S. S. Kostina, J. A. Peters, W. Lin, P. Chen, Z. Liu, P. L. Wang, M. G. Kanatzidis, B. W. Wessels

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Photoluminescence (PL) properties of semi-insulating Tl6SeI4 have been investigated. A broad emission band centered at 1.63 ± 0.02 eV was observed in all samples. The PL emission band is excitonic in nature and is tentatively attributed to a bound exciton emission. PL fatigue (a reduction in PL intensity under prolonged laser excitation) was always observed. The amount of PL fatigue depended on excitation power and temperature. PL fatigue kinetics are described by a stretched exponential with nominal lifetimes in the 10-265 s range. The recovery of the PL occurred within a few seconds of light cessation. The magnitude of PL fatigue in different samples correlated with inhomogeneous line broadening of the 1.63 eV emission band, such that broader bands exhibited more fatigue. An additional luminescence band centered at 1.78 eV was observed which increased in intensity under prolonged laser irradiation. The fatigue phenomenon is tentatively attributed to two mechanisms - the formation of photo-induced defects and the formation of quasi-stable particles. Both of these mechanisms introduce additional radiative and non-radiative recombination channels that lead to a decrease in the PL intensity under prolonged laser irradiation. Since inhomogeneous line broadening and PL fatigue are related to the concentration of defects or impurities, the measurement of these two parameters is an effective method to screen sample quality.

Original languageEnglish
Article number065009
JournalSemiconductor Science and Technology
Volume31
Issue number6
DOIs
Publication statusPublished - Apr 14 2016

Keywords

  • impurities
  • line broadening
  • metastable defects
  • photoluminescence
  • photoluminescence fatigue
  • quasi-stable particles
  • semiconductor

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Materials Chemistry
  • Condensed Matter Physics

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