scholarly journals Effect of Substrate Misorientation on the Structural and Optical Characteristics of In-Rich InGaAs/GaAsP Quantum Wells

2021 ◽  
Vol 11 (18) ◽  
pp. 8639
Author(s):  
Zhiwei Li ◽  
Yugang Zeng ◽  
Yue Song ◽  
Jianwei Zhang ◽  
Yinli Zhou ◽  
...  
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Chemical Vapor ◽  
Lattice Relaxation ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Peak Energy ◽  
Metal Organic ◽  
The Relationship

InGaAs quantum well (QW) lasers have attracted significant attention owing to their considerable potential for applications in optical communications; however, the relationship between the misorientation of the substrates used to grow InGaAs QWs and the structural and optical properties of QWs is still ambiguous. In this study, In-rich InGaAs/GaAsP single QWs were grown in the same run via metal organic chemical vapor deposition on GaAs (001) substrates misoriented by 0°, 2°, and 15° toward (111). The effects of substrate misorientation on the crystal quality and structural properties of InGaAs/GaAsP were investigated by X-ray diffraction and Raman spectroscopy. The 0° substrate exhibited the least lattice relaxation, and with increasing misorientation, the degree of lattice relaxation increased. The optical properties of the InGaAs/GaAsP QWs were investigated using temperature-dependent photoluminescence. An abnormal S-shaped variation of the peak energy and inverse evolution of the spectral bandwidth were observed at low temperatures for the 2° substrate, caused by the localization potentials due to the In-rich clusters. Surface morphology observations revealed that the growth mode varied with different miscuts. Based on the experimental results obtained in this study, a mechanism elucidating the effect of substrate miscuts on the structural and optical properties of QWs was proposed and verified.

Epitaxial Growth and Characterization of Nonpolar A-Plane AlGaN-Based Multiple Quantum Wells

2018 ◽  
Vol 934 ◽  
pp. 8-12
Author(s):  
Jian Guo Zhao ◽  
Xiong Zhang ◽  
Jia Qi He ◽  
Shuai Chen ◽  
Zi Li Wu ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Chemical Vapor ◽  
Multiple Quantum Wells ◽  
Modulation Method ◽  
Duty Ratio ◽  
Organic Chemical ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
Metal Organic

A serious of non-polar a-plane AlGaN-based multiple quantum wells (MQWs) were successfully grown on the semi-polar r-plane sapphire substrate with metal organic chemical vapor deposition technology. Intense MQWs-related emission peaks at an emission wavelength covered from 277-294 nm were observed based on the photoluminescence measurement. It was found that the employment of the trimethyl-aluminum (TMAl) flow duty-ratio modulation method which was developed based on the two-way pulsed-flows growth technique played a crucial role to control the Al composition of the non-polar a-plane AlGaN epi-layers. The non-polar a-plane AlGaN-based MQWs were deposited with the new developed TMAl flow duty-ratio modulation technique. Evident-3th order X-ray diffraction (XRD) satellite peak was observed from the high resolution-XRD measurement, proving the successful growth of non-polar a-plane AlGaN-based MQWs with abrupt hetero-interfaces.

scholarly journals Comparison Study of Structural and Optical Properties of InxGa1−xN/GaN Quantum Wells with Different In Compositions

2000 ◽  
Vol 5 (S1) ◽  
pp. 977-983
Author(s):  
Yong-Hwan Kwon ◽  
G. H. Gainer ◽  
S. Bidnyk ◽  
Y. H. Cho ◽  
J. J. Song ◽  
...  
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Chemical Vapor ◽  
Multiple Quantum ◽  
Nonradiative Recombination ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Recombination Rates ◽  
Satellite Peak ◽  
Interface Quality

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.

Structural and Optical Properties of α-Ga2O3 Films Deposited on Sapphire (10‾10) and (01‾12) Substrate by MOCVD

2013 ◽  
Vol 746 ◽  
pp. 369-373 ◽  
Author(s):  
Yu Lv ◽  
Wei Mi ◽  
Cai Na Luan ◽  
Jin Ma
Keyword(s):  
Optical Properties ◽  
Optical Band Gap ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Structural And Optical Properties ◽  
Visible Wavelength Range ◽  
Average Transmittance ◽  
Different Temperatures ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

Ga2O3thin films were grown on sapphire m-cut () and r-cut () orientations substrates at different temperatures by metal-organic chemical vapor deposition. Structural and optical properties of the Ga2O3films were investigated including the influence by annealing for the obtained films. The Ga2O3films on sapphire () and () substrate areα-Ga2O3. The crystallization of the films decreases after annealed at 900 °C. The average transmittance of the samples in the visible wavelength range was over 86% and the optical band gapEgwas about 4.755.15 eV. TheEgof the samples increases after annealing at 900 °C.

Structural and Optical Properties of InGaN/GaN Multi-Quantum Well Structures with Different Indium Compositions

2003 ◽  
Vol 764 ◽  
Author(s):  
Chang-Soo Kim ◽  
Sam-Kyu Noh ◽  
Kyuhan Lee ◽  
Sunwoon Kim ◽  
Jay P. Song
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Lattice Relaxation ◽  
Multiple Quantum ◽  
Structural And Optical Properties ◽  
Rich Region ◽  
Quantum Well Structures ◽  
Peak Intensity ◽  
Peak Energy ◽  
Multi Quantum Well

AbstractThe structural and optical properties of InGaN/GaN multiple quantum wells (MQWs) grown on sapphire by MOCVD have been investigated using high-resolution XRD, PL and TEM. The samples consisted of 10 periods of InGaN wells with 6.5nm thickness. The designed indium compositions were 15, 20, 25 and 30% (samples C15, C20, C25, C30, respectively). The thickness of GaN barrier was 7.5nm. The MQW in sample C15 maintained lattice coherency with the GaN epilayer underneath, the MQWs in the other samples, however, experienced lattice relaxation. The crystallinity of the samples decreased considerably with In concentration. As In composition increased, PL peak energy showed a red-shift, and the FWHM of the peaks increased. The increase in the FWHM is attributed to the defects due to the lattice relaxation. For C25 the PL peak intensity increased sharply in spite of the defects due to the lattice relaxation of the sample. It is concluded that the results are related to the In-rich region due to indium phase separation which was observed by TEM image.

scholarly journals Strain-Reduced Micro-LEDs Grown Directly Using Partitioned Growth

2021 ◽  
Vol 9 ◽  
Author(s):  
Shunpeng Lu ◽  
Yiping Zhang ◽  
Zi-Hui Zhang ◽  
Ping Chieh Tsai ◽  
Xueliang Zhang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Power Performance ◽  
Chip Size ◽  
Metal Organic ◽  
Strain Release ◽  
Underlying Mechanisms ◽  
Organic Chemical Vapor Deposition

Strain-reduced micro-LEDs in 50 μm × 50 μm, 100 μm × 100 μm, 200 μm × 200 μm, 500 μm × 500 μm, and 1,000 μm × 1,000 μm sizes were grown on a patterned c-plane sapphire substrate using partitioned growth with the metal-organic chemical-vapor deposition (MOCVD) technique. The size effect on the optical properties and the indium concentration for the quantum wells were studied experimentally. Here, we revealed that the optical properties can be improved by decreasing the chip size (from 1,000 to 100 µm), which can correspondingly reduce the in-plane compressive stress. However, when the chip size is further reduced to 50 μm × 50 μm, the benefit of strain release is overridden by additional defects induced by the higher indium incorporation in the quantum wells and the efficiency of the device decreases. The underlying mechanisms of the changing output power are uncovered based on different methods of characterization. This work shows the rules of thumb to achieve optimal power performance for strain-reduced micro-LEDs through the proposed partitioned growth process.

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