Photoluminescence fatigue and inhomogeneous line broadening in semi-insulating Tl₆ SeI₄ single crystals

Journal Article · Thu Apr 14 00:00:00 EDT 2016 · Semiconductor Science and Technology

DOI:https://doi.org/10.1088/0268-1242/31/6/065009· OSTI ID:1494817

Kostina, S. S. ^[1]; Peters, J. A. ^[2]; Lin, W. ^[3]; Chen, P.  ^[1]; Liu, Z. ^[1]; Wang, P. L. ^[3]; Kanatzidis, M. G. ^[4]; Wessels, B. W. ^[1]

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1. Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering
2. Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering; Chicago State Univ., IL (United States). Dept. of Chemistry and Physics
3. Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry
4. Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering, and Dept. of Chemistry

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. Finally, 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.

• Research Organization: Northwestern Univ., Evanston, IL (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation; US Department of Homeland Security (DHS)
• Grant/Contract Number: NA0002522; DN-077-ARI086-01
• OSTI ID: 1494817
• Alternate ID(s): OSTI ID: 1247433
• Journal Information: Semiconductor Science and Technology, Vol. 31, Issue 6; ISSN 0268-1242
• Publisher: IOP Publishing
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE