Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings

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PhysRevB.88.155322
Rights statement: ©2013 American Physical Society
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https://doi.org/10.1103/PhysRevB.88.155322
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quantum dot, quantum ring, photoluminescence

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Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings. / Hodgson, Peter ; Young, Robert; Ahmad Kamarudin, Mazliana et al.
In: Physical review B, Vol. 88, No. 15, 155322, 28.10.2013.

Research output: Contribution to Journal/Magazine › Journal article › peer-review

Bibtex

@article{95523c3c7efa4afbb6bb85f6bb4ae3ed,

title = "Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings",

abstract = "We present the results of photoluminescence (PL) measurements on a type-II GaSb/GaAs quantum dot/ring sample as a function of temperature (2 to 400 K) and over six orders of magnitude of incident laser excitation power. Optically induced charge depletion (OICD) was seen in both the wetting layer (WL) and quantum dots/rings but with remarkably different temperature dependent behavior. Holes originating from background acceptors migrate out of the WL as the sample temperature is raised to 30 K, while the onset of a blueshift in the PL from quantum rings, signaling their thermally induced charging with holes, is only observed at temperatures above 300 K. The presence of dark dots as a hidden reservoir for acceptor holes at the intermediate temperatures is proposed to explain this anomalous behavior. Due to the deep localization potential of GaSb/GaAs, thermalization of acceptor holes between dark dots and bright rings only occurs above room temperature. A rate equation model is presented which successfully replicates the main features of OICD observed here and in previous reports.",

keywords = "quantum dot, quantum ring, photoluminescence",

author = "Peter Hodgson and Robert Young and {Ahmad Kamarudin}, Mazliana and Qiandong Zhuang and Manus Hayne",

note = "{\textcopyright}2013 American Physical Society",

year = "2013",

month = oct,

day = "28",

doi = "10.1103/PhysRevB.88.155322",

language = "English",

volume = "88",

journal = "Physical review B",

issn = "1550-235X",

publisher = "AMER PHYSICAL SOC",

number = "15",

}

RIS

TY - JOUR

T1 - Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings

AU - Hodgson, Peter

AU - Young, Robert

AU - Ahmad Kamarudin, Mazliana

AU - Zhuang, Qiandong

AU - Hayne, Manus

PY - 2013/10/28

Y1 - 2013/10/28

N2 - We present the results of photoluminescence (PL) measurements on a type-II GaSb/GaAs quantum dot/ring sample as a function of temperature (2 to 400 K) and over six orders of magnitude of incident laser excitation power. Optically induced charge depletion (OICD) was seen in both the wetting layer (WL) and quantum dots/rings but with remarkably different temperature dependent behavior. Holes originating from background acceptors migrate out of the WL as the sample temperature is raised to 30 K, while the onset of a blueshift in the PL from quantum rings, signaling their thermally induced charging with holes, is only observed at temperatures above 300 K. The presence of dark dots as a hidden reservoir for acceptor holes at the intermediate temperatures is proposed to explain this anomalous behavior. Due to the deep localization potential of GaSb/GaAs, thermalization of acceptor holes between dark dots and bright rings only occurs above room temperature. A rate equation model is presented which successfully replicates the main features of OICD observed here and in previous reports.

AB - We present the results of photoluminescence (PL) measurements on a type-II GaSb/GaAs quantum dot/ring sample as a function of temperature (2 to 400 K) and over six orders of magnitude of incident laser excitation power. Optically induced charge depletion (OICD) was seen in both the wetting layer (WL) and quantum dots/rings but with remarkably different temperature dependent behavior. Holes originating from background acceptors migrate out of the WL as the sample temperature is raised to 30 K, while the onset of a blueshift in the PL from quantum rings, signaling their thermally induced charging with holes, is only observed at temperatures above 300 K. The presence of dark dots as a hidden reservoir for acceptor holes at the intermediate temperatures is proposed to explain this anomalous behavior. Due to the deep localization potential of GaSb/GaAs, thermalization of acceptor holes between dark dots and bright rings only occurs above room temperature. A rate equation model is presented which successfully replicates the main features of OICD observed here and in previous reports.

KW - quantum dot

KW - quantum ring

KW - photoluminescence

U2 - 10.1103/PhysRevB.88.155322

DO - 10.1103/PhysRevB.88.155322

M3 - Journal article

VL - 88

JO - Physical review B

JF - Physical review B

SN - 1550-235X

IS - 15

M1 - 155322

ER -

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