標題: Properties of defect traps in triple-stack InAs/GaAs quantum dots and effect of annealing
作者: Chen, JF
Hsiao, RS
Shih, SH
Wang, PY
Wang, JS
Chi, JY
電子物理學系
Department of Electrophysics
關鍵字: InAs/GaAs quantum dots;annealing;defect traps;deep level transient spectroscopy
公開日期: 15-Sep-2004
摘要: The electrical and optical properties of the defect traps, with and without annealing, in InAs/GaAs quantum dots (QDs) emitting at 1.3 mum are investigated by capacitance-voltage (C-V), deep-level transient spectroscopy (DLTS) and photoluminescence (PL). When increasing the InAs thickness to 3 ML, an abnormal temperature dependence of the C-V characteristic was observed in the triple-stack InAs/GaAs QD sample. This temperature dependence is attributed to the defect levels at 0.39 and 0.54 eV observed in DLTS. The level at 0.39 eV, found in the top GaAs barrier, is probably related to the relaxation-induced dislocations. The level at 0.54 eV is found close to the QD region. Rapid thermal annealing can reduce the concentrations of both levels. Comparing with PL result, which shows a blueshift of 140 meV and linewidth narrowing in the QD emission by annealing at 800degreesC, the level at 0.54 eV is speculated to be strain- or relaxation-related defects in the interface between the QDs and the barrier. Removal of this level by high-temperature RTA is important since this level lies close to the QDs and influences the optical quality of the QDs.
URI: http://dx.doi.org/10.1143/JJAP.43.L1150
http://hdl.handle.net/11536/26380
ISSN: 0021-4922
DOI: 10.1143/JJAP.43.L1150
期刊: JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS
Volume: 43
Issue: 9A-B
起始頁: L1150
結束頁: L1153
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