Photocurrent spectroscopy of InAs/GaAs self-assembled quantum dots: observation of a permanent dipole moment

被引：0

作者：

Fry, P.W. ^{[1
]}

Itskevich, I.E. ^{[1
]}

Mowbray, D.J. ^{[1
]}

Skolnick, M.S. ^{[1
]}

Barker, J.A. ^{[1
]}

O'Reilly, E.P. ^{[1
]}

Wilson, L.R. ^{[1
]}

Larkin, I.A. ^{[1
]}

Maksym, P.A. ^{[1
]}

Hopkinson, M. ^{[1
]}

Al-Khafaji, M. ^{[1
]}

David, J.P.R. ^{[1
]}

Cullis, A.G. ^{[1
]}

Hill, G. ^{[1
]}

Clark, J.C. ^{[1
]}

机构：

[1] Univ of Sheffield, Sheffield, United Kingdom

来源：

| 2000年 / Materials Research Society, Warrendale, PA, United States卷 / 571期

基金：

英国工程与自然科学研究理事会;

关键词：

Charge carriers - Electric fields - Electron energy levels - Electron tunneling - Hole traps - Numerical analysis - Photocurrents - Semiconducting gallium arsenide - Semiconducting indium compounds - Spectroscopy;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

Photocurrent spectroscopy of InAs/GaAs self-assembled quantum dots, studied as a function of applied electric field, is used to probe the nature of the confined electronic states. A field asymmetry of the quantum confined Stark effect is observed, consistent with the dots possessing a permanent dipole moment. The sign of this dipole indicates that for zero field the hole wavefunction lies above that of the electron, in disagreement with the predictions of all recent calculations. Comparison with a theoretical model demonstrates that the experimentally determined alignment of the electron and hole can only be explained if the dots contain a non-zero and non-uniform Ga content. The role of two different carrier escape mechanisms, tunneling and thermal excitation, is studied.

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