Influence of cap layer thickness on optical quality in In0.2Ga0.8As/GaAs single quantum wells

1994 ◽  
Vol 65 (3) ◽  
pp. 336-337 ◽  
Author(s):  
S. M. Wang ◽  
J. V. Thordson ◽  
T. G. Andersson ◽  
S. Jiang ◽  
L. X. Yang ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Layer Thickness ◽  
Optical Quality ◽  
Single Quantum ◽  
Cap Layer

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 ◽  
...  
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.

Optical and structural characteristics of high indium content InGaN/GaN multi-quantum wells with varying GaN cap layer thickness

2015 ◽  
Vol 117 (5) ◽  
pp. 055709 ◽  
Author(s):  
J. Yang ◽  
D. G. Zhao ◽  
D. S. Jiang ◽  
P. Chen ◽  
J. J. Zhu ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Layer Thickness ◽  
Structural Characteristics ◽  
Indium Content ◽  
Cap Layer ◽  
High Indium Content

Photoluminescence Investigations of High Purity Mbe-Grown Sil−xGex/Si Single Quantum Wells

1993 ◽  
Vol 298 ◽  
Author(s):  
M. Wachter ◽  
F. Schdffler ◽  
K. Thonke ◽  
R. Sauer ◽  
H.-J. Herzog ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Strain Energy ◽  
Free Exciton ◽  
Sige Layer ◽  
Band Edge ◽  
Background Concentration ◽  
Single Quantum ◽  
Single Quantum Well ◽  
Cap Layer ◽  
Shallow Impurities

AbstractSil-xGex/Si(100) single quantum well samples were grown by MBE with x varying from 18.5% to 36%, well widths Lz from 1.1 nm to 175 nm, and growth temperatures To in the range from 350°C to 750°C. We studied the photoluminescence (PL) properties in detail using Fourier transform spectroscopy. In most of the samples, the dominant and phononresolved SiGe band edge PL exhibits exclusively free exciton luminescence even at sample temperatures as low as 2 K. From the absence of bound excitons we conclude that the background concentration of shallow impurities is low in our SiGe layers. Variation of the growth temperature of the Si cap layer strongly influences the efficiency of the SiGe band edge PL at higher temperatures, whereas the PL efficiency is less affected at T=4 K. This indicates a reduction of the concentration of non-radiative defects in the cap layer when it is grown at higher temperatures. A broad PL band 150 meV below the SiGe bandgap, supposed to be typical for MBE-grown material, is weakly observed in only a few samples. The strength of the broad PL band does not unambiguously depend on the strain energy density in the SiGe layer as recently suggested.

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