OPTICAL PROPERTIES AND CARRIER DYNAMICS IN ASYMMETRIC COUPLED InGaN MULTIPLE QUANTUM WELLS

Optical properties and carrier dynamics of InGaN/GaN asymmetric coupled quantum wells (ACQWs) are studied by excitation-power-dependent photoluminescence (PL), photoreflectance (PR) and time-resolved PL (TRPL) experiments. Under weak excitations, only the emission from the widest well is observed due to the tunneling from narrower to wider wells. Under strong excitations, the carrier distribution becomes more uniform and an enhanced emission from the mid well (2.5 nm well) is observed. Dependence of the PL intensity on excitation power is well explained by a rate equation model. The energy levels in the ACQW structure are clearly revealed by PR measurements and are in good agreement with calculations. Our results indicate that the enhanced emission from the mid well is ascribed to "reverse tunneling" from 3.0 to 2.5 nm well, which is confirmed by TRPL experiments.

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Spatially and Time-Resolved Carrier Dynamics in Core–Shell InGaN/GaN Multiple-Quantum Wells on GaN Wire

Nano Letters ◽

10.1021/acs.nanolett.1c02760 ◽

2021 ◽

Author(s):

Jaime Segura-Ruiz ◽

Damien Salomon ◽

Andrei Rogalev ◽

Joël Eymery ◽

Benito Alén ◽

...

Keyword(s):

Quantum Wells ◽

Carrier Dynamics ◽

Multiple Quantum Wells ◽

Core Shell ◽

Multiple Quantum ◽

Time Resolved

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Interface Roughness of Quantum Wells Studied by Time-Resolved Photoluminescence

MRS Proceedings ◽

10.1557/proc-148-361 ◽

1989 ◽

Vol 148 ◽

Author(s):

H. X. Jiang ◽

P. Zhou ◽

S. A. Solin ◽

G. Bai

Keyword(s):

Optical Properties ◽

Quantum Wells ◽

Delay Time ◽

Interface Roughness ◽

Multiple Quantum ◽

Exciton Peak ◽

Exciton Luminescence ◽

Roughness Effects ◽

Time Resolved ◽

Time Resolved Photoluminescence

ABSTRACTOptical properties of GaAs-Al0 5Ga0 5As multiple quantum wells affected by interface roughness have been investigated by timeresolved photoluminescence. The interface roughness affects on exciton dynamics is shown to be more complicated than those previously well studied line-width broadening of exciton transitions. A two-exponential decay of exciton luminescence and exciton peak shifting with increasing delay time have been observed. These observations have been successfully interpreted in terms of the interface roughness effects.

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Similarities in the Optical Properties of Hexagonal and Cubic InGaN Quantum Wells

MRS Proceedings ◽

10.1557/proc-693-i7.5.1 ◽

2001 ◽

Vol 693 ◽

Author(s):

S. F. Chichibu ◽

M. Sugiyama ◽

T. Onuma ◽

T. Kuroda ◽

A. Tackeuchi ◽

...

Keyword(s):

Optical Properties ◽

Quantum Wells ◽

Multiple Quantum Well ◽

Intrinsic Property ◽

Multiple Quantum ◽

Time Resolved ◽

Exciton Localization ◽

Peak Energy ◽

Stretched Exponential Decay ◽

Ingan Quantum Wells

AbstractOptical properties of fully-strained wurtzite and zincblende InxGa1-xN/GaN multiple quantum well (MQW) structures were compared to discuss the origin of exciton localization. In contrast to the hexagonal InGaN MQWs, the photoluminescence (PL) peak energy of cubic InGaN MQWs showed a moderate blueshift with decreasing well thickness, L, and low-temperature PL decay time of the cubic MQWs did not depend strongly on L. The results imply that the wavefunction overlap in cubic InGaN MQWs was not reduced compared to the hexagonal ones, since they do not suffer from the electric field normal to the QW plane due either to spontaneous or piezoelectric polarization. Both MQWs exhibited a large and composition-dependent bandgap bowing, and time-resolved PL (TR-PL) signals showed a stretched-exponential decay even at room temperature. The exciton localization is considered to be an intrinsic property of InGaN.

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Investigations on the Optical Properties of InGaN/GaN Multiple Quantum Wells with Varying GaN Cap Layer Thickness

Nanoscale Research Letters ◽

10.1186/s11671-020-03420-y ◽

2020 ◽

Vol 15 (1) ◽

Author(s):

Xiaowei Wang ◽

Feng Liang ◽

Degang Zhao ◽

Zongshun Liu ◽

Jianjun Zhu ◽

...

Keyword(s):

Optical Properties ◽

Quantum Wells ◽

Layer Thickness ◽

Stark Effect ◽

Chemical Vapor ◽

Multiple Quantum ◽

Three Samples ◽

Measurement Results ◽

Cap Layer ◽

The Difference

Abstract Three InGaN/GaN MQWs samples with varying GaN cap layer thickness were grown by metalorganic chemical vapor deposition (MOCVD) to investigate the optical properties. We found that a thicker cap layer is more effective in preventing the evaporation of the In composition in the InGaN quantum well layer. Furthermore, the quantum-confined Stark effect (QCSE) is enhanced with increasing the thickness of GaN cap layer. In addition, compared with the electroluminescence measurement results, we focus on the difference of localization states and defects in three samples induced by various cap thickness to explain the anomalies in room temperature photoluminescence measurements. We found that too thin GaN cap layer will exacerbates the inhomogeneity of localization states in InGaN QW layer, and too thick GaN cap layer will generate more defects in GaN cap layer.

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Study of electron-related intersubband optical properties in three coupled quantum wells wires with triangular transversal section

Superlattices and Microstructures ◽

10.1016/j.spmi.2015.05.038 ◽

2015 ◽

Vol 87 ◽

pp. 131-136 ◽

Cited By ~ 3

Author(s):

A. Tiutiunnyk ◽

V. Tulupenko ◽

V. Akimov ◽

R. Demediuk ◽

A.L. Morales ◽

...

Keyword(s):

Optical Properties ◽

Quantum Wells ◽

Coupled Quantum Wells ◽

Transversal Section

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Optical Study of Localized and Delocalized States in GaAsN/GaAs

MRS Proceedings ◽

10.1557/proc-798-y5.68 ◽

2003 ◽

Vol 798 ◽

Author(s):

Z. Y. Xu ◽

X. D. Luo ◽

X. D. Yang ◽

P. H. Tan ◽

C. L. Yang ◽

...

Keyword(s):

Quantum Wells ◽

Rapid Thermal Annealing ◽

Short Pulse ◽

Selective Excitation ◽

Excitation Power ◽

Pulse Excitation ◽

Optical Study ◽

Time Resolved ◽

Exciton Localization ◽

Time Resolved Photoluminescence

ABSTRACTTaking advantages of short pulse excitation and time-resolved photoluminescence (PL), we have studied the exciton localization effect in a number of GaAsN alloys and GaAsN/GaAs quantum wells (QWs). In the PL spectra, an extra transition located at the higher energy side of the commonly reported N-related emissions is observed. By measuring PL dependence on temperature and excitation power along with PL dynamics study, the new PL peak has been identified as a transition of the band edge-related recombination in dilute GaAsN alloy and delocalized transition in QWs. Using selective excitation PL we further attribute the localized emission in QWs to the excitons localized at the GaAsN/GaAs interfaces. This interface-related exciton localization could be greatly reduced by a rapid thermal annealing.

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UV Emission Mechanisms in Quaternary AlInGaN Epilayers and Multiple Quantum Wells

MRS Proceedings ◽

10.1557/proc-722-k1.7 ◽

2002 ◽

Vol 722 ◽

Author(s):

Mee-Yi Ryu ◽

C. Q. Chen ◽

E. Kuokstis ◽

J. W. Yang ◽

G. Simin ◽

...

Keyword(s):

Quantum Wells ◽

Light Emitting Diode ◽

Chemical Vapor ◽

Excitation Power ◽

Multiple Quantum Wells ◽

Multiple Quantum ◽

Excitation Power Density ◽

Light Emitting ◽

Uv Emission ◽

Alloy Disorder

AbstractWe present the results on investigation and analysis of photoluminescence (PL) dynamics of quaternary AlInGaN epilayers and AlInGaN/AlInGaN multiple quantum wells (MQWs) grown by a novel pulsed metalorganic chemical vapor deposition (PMOCVD). The emission peaks in both AlInGaN epilayers and MQWs show a blueshift with increasing excitation power density. The PL emission of quaternary samples is attributed to recombination of carriers/excitons localized at band-tail states. The PL decay time increases with decreasing emission photon energy, which is a characteristic of localized carrier/exciton recombination due to alloy disorder. The obtained properties of AlInGaN materials grown by a PMOCVD are similar to those of InGaN. This indicates that the AlInGaN system is promising for ultraviolet applications such as the InGaN system for blue light emitting diode and laser diode applications.

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