Extremely low inhomogeneous broadening of exciton lines in shallow (In,Ga)As/GaAs quantum wells

• Published in: arXiv.org
• Main Authors: Poltavtsev, S V, Efimov, Yu P, Dolgikh, Yu K, Eliseev, S A, Petrov, V V, Ovsyankin, V V
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 30.06.2014
• Subjects: Excitons; Gallium arsenide; Physics - Mesoscale and Nanoscale Physics; Physics - Optics; Quantum wells; Reflection; Spectrum analysis
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1406.7670

We study radiative linewidth of exciton resonance in shallow In\(_x\)Ga\(_{1-x}\)As/GaAs single quantum wells as a function of indium concentration in the range \(x=0.02...0.10\) and well thickness in the range \(L_Z=1...30\) nm using the method of Brewster reflection spectroscopy. Record linewidths of heavy-hole exciton resonance of about 130...180 \(\mu\)eV are measured in reflection spectra for single quantum wells with \(L_Z=2\) nm and \(x=0.02\) at temperature 9 K. In these spectra, the non-radiative linewidth including inhomogeneous broadening can be comparable or even less than radiative linewidth. It is shown that radiative linewidth weakly depends on \(x\) and \(L_Z\) in these ranges. In multiple-quantum-well Bragg structure with ten periods radiative linewidth exceeds inhomogeneous broadening by 4 times.