Interplay effects of temperature and injection power on photoluminescence of InAs/GaAs quantum dot with high and low areal density

• Published in: Journal of physics. D, Applied physics Vol. 43; no. 48; p. 485102
• Main Authors: Zhou, X L, Chen, Y H, Jia, C H, Ye, X L, Xu, Bo, Wang, Z G
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 08.12.2010; Institute of Physics
• Subjects: Carriers; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Density; Exact sciences and technology; Gallium arsenide; Gallium arsenides; Indium arsenides; Intervals; Materials science; Methods of nanofabrication; Nanoscale materials and structures: fabrication and characterization; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Photoluminescence; Physics; Quantum dots; Self-assembly; Temperature dependence; Quantum system; Gallium arsenides; High density; Quantum dots; Photoluminescence; Indium arsenides; III-V compound; Self-assembly; Excitons; Temperature effects; Rate equation; Nanostructured materials; III-V semiconductors
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/43/48/485102

In this report, we have investigated the temperature and injection power dependent photoluminescence in self-assembled InAs/GaAs quantum dots (QDs) systems with low and high areal density, respectively. It was found that, for the high-density samples, state filling effect and abnormal temperature dependence were interacting. In particular, the injection power-induced variations were most obvious at the temperature interval where carriers transfer from small quantum dots (SQDs) to large quantum dots (LQDs). Such interplay effects could be explained by carrier population of SQDs relative to LQDs, which could be fitted well using a thermal carrier rate equation model. On the other hand, for the low density sample, an abnormal broadening of full width at half maximum (FWHM) was observed at the 15–100 K interval. In addition, the FWHM also broadened with increasing injection power at the whole measured temperature interval. Such peculiarities of low density QDs could be attributed to the exciton dephasing processes, which is similar to the characteristic of a single quantum dot. The compared interplay effects of high- and low-density QDs reflect the difference between an interacting and isolated QDs system.