Localization versus carrier-screening effects in InGaN quantum wells — A time-resolved cathodoluminescence study

2005 ◽  
Author(s):  
A. Bell
Keyword(s):  
Quantum Wells ◽  
Carrier Screening ◽  
Time Resolved ◽  
Ingan Quantum Wells ◽  
Cathodoluminescence Study

scholarly journals Enhancement of quantum efficiency in InGaN quantum wells by using superlattice interlayers and pulsed growth

2016 ◽  
Vol 55 (4) ◽  
Author(s):  
Kazimieras Nomeika ◽  
Mantas Dmukauskas ◽  
Ramūnas Aleksiejūnas ◽  
Patrik Ščajev ◽  
Saulius Miasojedovas ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantum Efficiency ◽  
Light Emitting Diode ◽  
Internal Quantum Efficiency ◽  
Recombination Coefficient ◽  
Time Resolved ◽  
Mocvd Growth ◽  
Lower Strain ◽  
Type Contact ◽  
Ingan Quantum Wells

Enhancement of internal quantum efficiency (IQE) in InGaN quantum wells by insertion of a superlattice interlayer and applying the pulsed growth regime is investigated by a set of time-resolved optical techniques. A threefold IQE increase was achieved in the structure with the superlattice. It was ascribed to the net effect of decreased internal electrical field due to lower strain and altered carrier localization conditions. Pulsed MOCVD growth also resulted in twice higher IQE, presumably due to better control of defects in the structure. An LED (light emitting diode) structure with a top p-type contact GaN layer was manufactured by using both growth techniques with the peak IQE equal to that in the underlying quantum well structure. The linear recombination coefficient was found to gradually increase with excitation due to carrier delocalization, and the latter dependence was successfully used to fit the IQE droop.

scholarly journals Spatio-Time-Resolved Cathodoluminescence Spectroscopy Imaging: Microscopic Recombination Kinetics in Semi-Polar InGaN Quantum Wells

2010 ◽  
Vol 16 (S2) ◽  
pp. 812-813
Author(s):  
J Christen ◽  
F Bertram ◽  
S Metzner ◽  
T Wunderer ◽  
F Lipski ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Time Resolved ◽  
Cathodoluminescence Spectroscopy ◽  
Recombination Kinetics ◽  
Ingan Quantum Wells

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

Phonon satellites and time-resolved studies of carrier recombination dynamics in InGaN quantum wells

2007 ◽  
Vol 41 (5-6) ◽  
pp. 419-424 ◽  
Author(s):  
S.M. Olaizola ◽  
W.H. Fan ◽  
D.J. Mowbray ◽  
M.S. Skolnick ◽  
P.J. Parbrook ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Time Resolved ◽  
Carrier Recombination ◽  
Recombination Dynamics ◽  
Ingan Quantum Wells

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

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.

scholarly journals The impact of point defects in n-type GaN layers on thermal decomposition of InGaN/GaN QWs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mikolaj Grabowski ◽  
Ewa Grzanka ◽  
Szymon Grzanka ◽  
Artur Lachowski ◽  
Julita Smalc-Koziorowska ◽  
...  
Keyword(s):  
Quantum Wells ◽  
High Temperatures ◽  
Point Defects ◽  
X Ray Diffraction ◽  
Helium Ions ◽  
X Ray ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
The Impact ◽  
Ingan Quantum Wells

AbstractThe aim of this paper is to give an experimental evidence that point defects (most probably gallium vacancies) induce decomposition of InGaN quantum wells (QWs) at high temperatures. In the experiment performed, we implanted GaN:Si/sapphire substrates with helium ions in order to introduce a high density of point defects. Then, we grew InGaN QWs on such substrates at temperature of 730 °C, what caused elimination of most (but not all) of the implantation-induced point defects expanding the crystal lattice. The InGaN QWs were almost identical to those grown on unimplanted GaN substrates. In the next step of the experiment, we annealed samples grown on unimplanted and implanted GaN at temperatures of 900 °C, 920 °C and 940 °C for half an hour. The samples were examined using Photoluminescence, X-ray Diffraction and Transmission Electron Microscopy. We found out that the decomposition of InGaN QWs started at lower temperatures for the samples grown on the implanted GaN substrates what provides a strong experimental support that point defects play important role in InGaN decomposition at high temperatures.

Rational construction of staggered InGaN quantum wells for efficient yellow light-emitting diodes

2021 ◽  
Vol 118 (18) ◽  
pp. 182102
Author(s):  
Xiaoyu Zhao ◽  
Bin Tang ◽  
Liyan Gong ◽  
Junchun Bai ◽  
Jiafeng Ping ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Light Emitting Diodes ◽  
Yellow Light ◽  
Light Emitting ◽  
Rational Construction ◽  
Ingan Quantum Wells

Role of Metal Vacancies in the Mechanism of Thermal Degradation of InGaN Quantum Wells

2021 ◽  
Vol 13 (6) ◽  
pp. 7476-7484
Author(s):  
Julita Smalc-Koziorowska ◽  
Ewa Grzanka ◽  
Artur Lachowski ◽  
Roman Hrytsak ◽  
Mikolaj Grabowski ◽  
...  
Keyword(s):  
Thermal Degradation ◽  
Quantum Wells ◽  
Metal Vacancies ◽  
Ingan Quantum Wells
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