Optical detection of nonradiative recombination centers in AlGaN quantum wells for deep UV region

2014 ◽  
Vol 11 (3-4) ◽  
pp. 832-835 ◽  
Author(s):  
A. Z. M. Touhidul Islam ◽  
N. Murakoshi ◽  
T. Fukuda ◽  
H. Hirayama ◽  
N. Kamata
Keyword(s):  
Quantum Wells ◽  
Optical Detection ◽  
Nonradiative Recombination ◽  
Recombination Centers ◽  
Deep Uv

Nonradiative recombination centers in deep UV-wavelength AlGaN quantum wells detected by below-gap excitation light

2019 ◽  
Vol 58 (SC) ◽  
pp. SCCB37 ◽  
Author(s):  
M. Ismail Hossain ◽  
Yuri Itokazu ◽  
Shunsuke Kuwaba ◽  
Norihiko Kamata ◽  
Noritoshi Maeda ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Nonradiative Recombination ◽  
Excitation Light ◽  
Recombination Centers ◽  
Deep Uv

scholarly journals Photoluminescence Characterization of Nonradiative Recombination Centers in Light Emitting Materials by Utilizing Below-Gap Excitation: A Mini Review of Two-Wavelength Excited Photoluminescence

2015 ◽  
Vol 43 ◽  
pp. 1-9
Author(s):  
Norihiko Kamata ◽  
Abu Zafor Md. Touhidul Islam
Keyword(s):  
Quantum Wells ◽  
Electrical Contact ◽  
Intensity Change ◽  
Nonradiative Recombination ◽  
Excitation Light ◽  
Light Emitting ◽  
Recombination Centers ◽  
Pl Intensity ◽  
Trap Filling

We have developed an optical method of detecting and characterizing nonradiative recombination (NRR) centers without electrical contact. The method combines a below-gap excitation (BGE) light with a conventional above-gap excitation light in photoluminescence (PL) measurement, and discriminates the PL intensity change due to switching on and off the BGE. A quantitative analysis of the detected NRR centers became possible by utilizing the saturating tendency of the PL intensity change with increasing the BGE density due to trap filling effect. Some experimental results of AlGaAs, InGaN, and AlGaN quantum wells were shown to allocate the development and present status as well as to exemplify their interpretations.

Impacts of Si-doping on vacancy complex formation and their influences on deep ultraviolet luminescence dynamics in Al x Ga1-x N films and multiple quantum wells grown by metalorganic vapor phase epitaxy

2021 ◽  
Author(s):  
Shigefusa F. Chichibu ◽  
Hideto MIYAKE ◽  
Akira Uedono
Keyword(s):  
Quantum Wells ◽  
Vapor Phase ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Vapor Phase Epitaxy ◽  
Multiple Quantum ◽  
Nonradiative Recombination ◽  
Si Doping ◽  
Deep Ultraviolet ◽  
Si Doped ◽  
Recombination Centers

Abstract To give a clue for increasing emission efficiencies of Al x Ga1-x N-based deep ultraviolet light emitters, the origins and influences on carrier concentration and minority carrier lifetime (τminority), which determines the internal quantum efficiency, of midgap recombination centers in c-plane Si-doped Al0.60Ga0.40N epilayers and Al0.68Ga0.32N quantum wells (QWs) grown by metalorganic vapor phase epitaxy were studied by temporally and spatially resolved luminescence measurements, making a correlation with the results of positron annihilation measurement. For the Al0.60Ga0.40N epilayers, τminority decreased as the concentration of cation vacancies (VIII) increased, indicating that VIII, most probably decorated with nitrogen vacancies (VN), VIII(VN) n , are major nonradiative recombination centers (NRCs). For heavily Si-doped Al0.60Ga0.40N, a generation of electron-compensating complexes (VIII-SiIII) is suggested. For lightly Si-doping regime, τminority of the QW emission was increased by appropriate Si-doping in the wells, which simultaneously increased the terrace width. The importance of wetting conditions is suggested for decreasing the NRC concentration.

Hydrogen Passivation of Defects in InGaAs/AlxGal-xAs Quantum Wells

1992 ◽  
Vol 262 ◽  
Author(s):  
S. M. Lord ◽  
G. Roos ◽  
B. Pezeshki ◽  
J. S. Harris ◽  
N. M. Johnson
Keyword(s):  
Quantum Wells ◽  
Depth Distribution ◽  
Multilayered Structure ◽  
Nonradiative Recombination ◽  
Hydrogen Passivation ◽  
Defect Passivation ◽  
Recombination Centers ◽  
Pl Intensity ◽  
Secondary Ion

ABSTRACTThe effect of the diffusion of monatomic hydrogen into InGaAs/AlGaAs quantum wells has been investigated using photoluminescence (PL) and Secondary Ion Mass Spectroscopy (SIMS). The structures were grown by molecular beam epitaxy and hydrogenated with a remote plasma. For In0.2Ga0.8AlxGA1-xAs quantum wells, hydrogenation significant increases the integrated PL intensity from bound excitons at 77 K. The enhancement of the PL is ascribed to removal of nonradiative recombination centers by hydrogen passivation of defects either at the heterojunction interface or within the epilayers. This PL enhancement (and defect passivation) increases as the Al concentration in the AlGaAs layers increases from 0 to 33 at%. A 50% increase of PL intensity is observed for InGaAs/GaAs. For 33 at%, the increase is a factor of 9. We also diffused deuterium into these InGaAs/AlGaAs quantum wells. The enhancement of the PL by deuteration was similar to that by hydrogenation. The isotopie substitution permits the determination of the depth distribution of deuterium in the multilayered structure by SIMS. SIMS results support the conclusion that more defects are passivated in the higher Al concentration samples.

Mechanisms of exciton photoluminescence quenching in the electric field of a standing surface acoustic wave

2019 ◽  
Vol 33 (06) ◽  
pp. 1950032
Author(s):  
D. V. Gulyaev ◽  
K. S. Zhuravlev
Keyword(s):  
Acoustic Wave ◽  
Electric Field ◽  
Quantum Wells ◽  
Surface Acoustic Wave ◽  
Impact Ionization ◽  
Interface Roughness ◽  
Nonradiative Recombination ◽  
Recombination Centers ◽  
Subsequent Capture ◽  
The Impact

Mechanisms of exciton photoluminescence (PL) quenching in the longitudinal electric field of a standing surface acoustic wave (SAW) have been studied by the example of type II GaAs/AlAs superlattices (SLs). Such SLs with a long lifetime of nonequilibrium carriers have allowed examining the influence of the SAW electric field on the excitonic PL both under the continuous and impulse laser excitations. It has been found that the mechanisms of the interaction of excitons and a SAW electric field depend upon the kinetic energy of excitons and carriers. As for hot excitons and carriers, the standing SAW electric field causes the impact ionization of excitons with a subsequent capture of free carriers at the nonradiative recombination centers, which results in a decrease in the steady-state exciton PL. As for cold excitons and carriers, the impact of excitons with the carriers accelerated by the SAW electric field results mainly in exciton delocalization from the levels of quantum wells formed due to interface roughness with a subsequent capture of excitons at the nonradiative recombination centers, which leads to the acceleration of the PL kinetics.

scholarly journals XXIII Международный симпозиум Нанофизика и наноэлектроника", Нижний Новгород, 11-14 марта 2019 г. Гетероструктуры с GaAs/GaP-квантовыми ямами, выращенные на Si-подложках

2019 ◽  
Vol 53 (9) ◽  
pp. 1167
Author(s):  
Д.С. Абрамкин ◽  
М.О. Петрушков ◽  
М.А. Путято ◽  
Б.Р. Семягин ◽  
Е.А. Емельянов ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Temperature Stability ◽  
Nonradiative Recombination ◽  
High Concentration ◽  
Light Emitting ◽  
Highly Efficient ◽  
Hybrid Substrates ◽  
Recombination Centers ◽  
Lattice Matched

AbstractMolecular-beam epitaxy is used to produce GaP/Si hybrid substrates that allow the growth of highly efficient light-emitting heterostructures with GaAs/GaP quantum wells. Despite the relatively high concentration of nonradiative-recombination centers in GaP/Si layers, GaAs/GaP quantum-well heterostructures grown on GaP/Si hybrid substrates are highly competitive in terms of efficiency and temperature stability of luminescence to similar heterostructures grown on lattice-matched GaP substrates.

scholarly journals Role of dislocations in nitride laser diodes with different indium content

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Agata Bojarska-Cieślińska ◽  
Łucja Marona ◽  
Julita Smalc-Koziorowska ◽  
Szymon Grzanka ◽  
Jan Weyher ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Defect Density ◽  
Laser Diodes ◽  
Diffusion Path ◽  
Vapour Phase ◽  
Indium Content ◽  
Nonradiative Recombination ◽  
Light Emitters ◽  
Vapour Phase Epitaxy

AbstractIn this work we investigate the role of threading dislocations in nitride light emitters with different indium composition. We compare the properties of laser diodes grown on the low defect density GaN substrate with their counterparts grown on sapphire substrate in the same epitaxial process. All structures were produced by metalorganic vapour phase epitaxy and emit light in the range 383–477 nm. We observe that intensity of electroluminescence is strong in the whole spectral region for devices grown on GaN, but decreases rapidly for the devices on sapphire and emitting at wavelength shorter than 420 nm. We interpret this behaviour in terms of increasing importance of dislocation related nonradiative recombination for low indium content structures. Our studies show that edge dislocations are the main source of nonradiative recombination. We observe that long wavelength emitting structures are characterized by higher average light intensity in cathodoluminescence and better thermal stability. These findings indicate that diffusion path of carriers in these samples is shorter, limiting the amount of carriers reaching nonradiative recombination centers. According to TEM images only mixed dislocations open into the V-pits, usually above the multi quantum wells thus not influencing directly the emission.

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