砷化銦量子點之光譜研究
Date Issued
2005-07-31
Date
2005-07-31
Author(s)
DOI
932215E002041
Abstract
Two kinds of nanostructure samples grown by gas source molecular beam epitaxy were
studied by photoreflectance (PR) and photoluminescence (PL) spectroscopies. One is an
InGaP/GaAs heterojunction with a single quantum well (SQW) structure; and the second is an
InAs/GaAs self-assembled quantum dots (SAQD) sample.
Temperature-dependent PR and PL characterizations of the InAs/GaAs QD structures were
also performed. At 20 K, optical transitions due to the InAs QDs, wetting layers, and GaAs buffer
and cap layers were identified. Transition energies of the ground state and four excited states with
nearly equal interlevel spacings (75-80 meV) were observed. The linewidth of the ground-state
transition decreased as the temperature increased from 20 K to 100 K while the linewidth became
broader at temperatures above 100 K. Energy features of the PR spectra originating from QDs
and relating to the in-plane parabolic potentials were discussed. Theoretical calculation of optical
properties of pyramidal QDs was also performed including the strain effect. The eight-band
results were compared with the results calculated by in-plane parabolic potential and with the
experimental results.
Subjects
Quantum dot
Photoreflectance
Photoluminescence
Strain distribution
Publisher
臺北市：國立臺灣大學電子工程學研究所
Type
report
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