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

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Xiaowei Wang ◽  
Feng Liang ◽  
Degang Zhao ◽  
Zongshun Liu ◽  
Jianjun Zhu ◽  
...  

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.

2000 ◽  
Vol 5 (S1) ◽  
pp. 977-983
Author(s):  
Yong-Hwan Kwon ◽  
G. H. Gainer ◽  
S. Bidnyk ◽  
Y. H. Cho ◽  
J. J. Song ◽  
...  

The effect of In on the structural and optical properties of InxGa1−xN/GaN multiple quantum wells (MQWs) was investigated. These were five-period MQWs grown on sapphire by metalorganic chemical vapor deposition. Increasing the In composition caused broadening of the high-resolution x-ray diffraction superlattice satellite peak and the photoluminescence-excitation bandedge. This indicates that the higher In content degrades the interface quality because of nonuniform In incorporation into the GaN layer. However, the samples with higher In compositions have lower room temperature (RT) stimulated (SE) threshold densities and lower nonradiative recombination rates. The lower RT SE threshold densities of the higher In samples show that the suppression of nonradiative recombination by In overcomes the drawback of greater interface imperfection.


2015 ◽  
Vol 764-765 ◽  
pp. 1250-1254
Author(s):  
Ya Fen Wu ◽  
Jiunn Chyi Lee

The InGaN/AlGaN multiple-quantum-well heterostructures were fabricated by metal-organic chemical vapor deposition system with different indium and aluminum content during the growth of InGaN well layers and AlGaN barrier layers. Temperature-and incident-power-dependent photoluminescence were carried out to examine the recombination mechanisms in the heterostructures. Both of the localization effect and quantum-confined Stark effect are considered. From the experimental and theoretical analysis, the dependence of optical characteristics on the temperature and incident-power are consistent with the recombination mechanisms involving band-tail states and the screen of quantum-confined Stark effect.


1998 ◽  
Vol 537 ◽  
Author(s):  
T.J. Schmidt ◽  
S. Bidnyk ◽  
Yong-Hoon Cho ◽  
A.J. Fischer ◽  
J.J. Song ◽  
...  

AbstractOptically pumped stimulated emission (SE) from InGaN/GaN multiple quantum wells (MQWs) grown by metalorganic chemical vapor deposition has been systematically studied as a function of excitation length (Lexc). Two distinct SE peaks were observed from these structures: one that originates at 425 nm at 10 K (430 nm at 300 K) and another that originates at 434 nm at 10 K (438 nm at 300 K). The SE threshold for the high energy peak was observed to always be lower than that of the low energy peak, but the difference was found to decrease greatly with increasing Lexc. A detailed study of the emission intensity of these two SE peaks as a function of excitation density shows that the two peaks compete for gain in the MQW active region.


1999 ◽  
Vol 595 ◽  
Author(s):  
Yong-Hwan Kwon ◽  
G. H. Gainer ◽  
S. Bidnyk ◽  
Y. H. Cho ◽  
J. J. Song ◽  
...  

AbstractThe effect of In on the structural and optical properties of InxGa1−xN/GaN multiple quantum wells (MQWs) was investigated. These were five-period MQWs grown on sapphire by metalorganic chemical vapor deposition. Increasing the In composition caused broadening of the high-resolution x-ray diffraction superlattice satellite peak and the photoluminescence-excitation bandedge. This indicates that the higher In content degrades the interface quality because of nonuniform In incorporation into the GaN layer. However, the samples with higher In compositions have lower room temperature (RT) stimulated (SE) threshold densities and lower nonradiative recombination rates. The lower RT SE threshold densities of the higher In samples show that the suppression of nonradiative recombination by In overcomes the drawback of greater interface imperfection.


1999 ◽  
Vol 4 (S1) ◽  
pp. 757-762 ◽  
Author(s):  
T.J. Schmidt ◽  
S. Bidnyk ◽  
Yong-Hoon Cho ◽  
A.J. Fischer ◽  
J.J. Song ◽  
...  

Optically pumped stimulated emission (SE) from InGaN/GaN multiple quantum wells (MQWs) grown by metalorganic chemical vapor deposition has been systematically studied as a function of excitation length (Lexc). Two distinct SE peaks were observed from these structures: one that originates at 425 nm at 10 K (430 nm at 300 K) and another that originates at 434 nm at 10 K (438 nm at 300 K). The SE threshold for the high energy peak was observed to always be lower than that of the low energy peak, but the difference was found to decrease greatly with increasing Lexc. A detailed study of the emission intensity of these two SE peaks as a function of excitation density shows that the two peaks compete for gain in the MQW active region.


2012 ◽  
Vol 535-537 ◽  
pp. 1270-1274
Author(s):  
Li Jun Han ◽  
Bin Feng Ding ◽  
Guo Man Lin

The structural and optical properties of InxGa1-xN/GaN multi-quantum wells (MQWs) grown on sapphire are discussed. Two kinds of InxGa1-xN/GaN MQWs with same period and different single cycle thickness and different growth temperature of MQWs are selected. Firstly, from the result of SRXRD and RBS/C, we can estimate that indium content of InxGa1-xN /GaN MQWs is 0.033 and 0.056, the single cycle thickness of MQWs is 13.04nm and 15.86nm respectively. Secondly the PL results indicate the optical properties of InxGa1-xN/GaN MQWs. Finally, we find indium content decreasing with increasing growth temperature of MQWs and the emission intensity reducing with temperature increasing, the emission optical peak position versus temperature show the “S-shaped” character. All these experimental results testify the material design of InxGa1-xN/GaN MQWs will have potential applications in spectral LED.


1993 ◽  
Vol 21 (2-3) ◽  
pp. 198-200 ◽  
Author(s):  
J. Dreybrodt ◽  
F. Faller ◽  
A. Forchel ◽  
J.P. Reithmaier

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