Effects of biased and unbiased illuminations on two-dimensional electron gases in dopant-free GaAs/AlGaAs

被引：5

作者：

Shetty, A. ^{[1
,2
]}

Sfigakis, F. ^{[1
,2
,3
,4
]}

Mak, W. Y. ^{[3
]}

Das Gupta, K. ^{[5
]}

Buonacorsi, B. ^{[1
,6
]}

Tam, M. C. ^{[7
]}

Kim, H. S. ^{[7
]}

Farrer, I ^{[3
,8
]}

Croxall, A. F. ^{[3
]}

Beere, H. E. ^{[3
]}

Hamilton, A. R. ^{[9
]}

Pepper, M. ^{[10
]}

Austing, D. G. ^{[11
]}

Studenikin, S. A. ^{[11
]}

Sachrajda, A. ^{[11
]}

Reimer, M. E. ^{[1
,4
,6
,7
]}

Wasilewski, Z. R. ^{[1
,4
,6
,7
,12
]}

Ritchie, D. A. ^{[3
]}

Baugh, J. ^{[1
,2
,4
,6
,12
]}

机构：

[1] Univ Waterloo, Inst Quantum Comp, Waterloo, ON N2L 3G1, Canada

[2] Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada

[3] Univ Cambridge, Cavendish Lab, Cambridge CB3 0HE, England

[4] Northern Quantum Lights Inc, Waterloo, ON N2B 1N5, Canada

[5] Indian Inst Technol, Dept Phys, Mumbai 40007, Maharashtra, India

[6] Univ Waterloo, Dept Phys & Astron, Waterloo, ON N2L 3G1, Canada

[7] Univ Waterloo, Dept Elect & Comp Engn, Waterloo, ON N2L 3G1, Canada

[8] Univ Sheffield, Dept Elect & Elect Engn, Sheffield S1 3JD, S Yorkshire, England

[9] Univ New South Wales, Sch Phys, Sydney, NSW 2052, Australia

[10] UCL, Dept Elect & Elect Engn, London WC1E 7JE, England

[11] Natl Res Council Canada, Secur & Disrupt Technol Res Ctr, Ottawa, ON K1A 0R6, Canada

[12] Univ Waterloo, Waterloo Inst Nanotechnol, Waterloo, ON N2L 3G1, Canada

来源：

PHYSICAL REVIEW B | 2022年 / 105卷 / 07期

基金：

加拿大自然科学与工程研究理事会; 英国工程与自然科学研究理事会;

关键词：

PERSISTENT PHOTOCONDUCTIVITY; UNDOPED HETEROSTRUCTURE; MOBILITY ENHANCEMENT; HOLE GASES; DEEP DONOR; DX-CENTER; GAAS; SCATTERING; LAYERS; TRANSPORT;

D O I：

10.1103/PhysRevB.105.075302

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Illumination is performed at low temperature on dopant-free two-dimensional electron gases (2DEGs) of varying depths, under unbiased (gates grounded) and biased (gates at a positive or negative voltage) conditions. Unbiased illuminations in 2DEGs located more than 70 nm away from the surface result in a gain in mobility at a given electron density, primarily driven by the reduction of background impurities. In 2DEGs closer to the surface, unbiased illuminations result in a mobility loss, driven by an increase in surface charge density. Biased illuminations performed with positive applied gate voltages result in a mobility gain, whereas those performed with negative applied voltages result in a mobility loss. The magnitude of the mobility gain (loss) weakens with 2DEG depth, and is likely driven by a reduction (increase) in surface charge density. Remarkably, this mobility gain/loss is fully reversible by performing another biased illumination with the appropriate gate voltage, provided both n-type and p-type Ohmic contacts are present. Experimental results are modeled with Boltzmann transport theory, and possible mechanisms are discussed.

引用

页数：16

共 81 条

[41] TRAPPING CHARACTERISTICS AND A DONOR-COMPLEX (DX) MODEL FOR THE PERSISTENT PHOTOCONDUCTIVITY TRAPPING CENTER IN TE-DOPED ALXGA1-XAS [J].