scholarly journals Intersubband Transition Engineering in the Conduction Band of Asymmetric Coupled Ge/SiGe Quantum Wells

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 179 ◽  
Author(s):  
Luca Persichetti ◽  
Michele Montanari ◽  
Chiara Ciano ◽  
Luciana Di Gaspare ◽  
Michele Ortolani ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Conduction Band ◽  
Tunnel Barrier ◽  
Interface Quality ◽  
Coupled Quantum Wells ◽  
Light Emitting ◽  
Quantum Cascade ◽  
Structural Interface ◽  
Silicon Based

n-type Ge/SiGe asymmetric coupled quantum wells represent the building block of a variety of nanoscale quantum devices, including recently proposed designs for a silicon-based THz quantum cascade laser. In this paper, we combine structural and spectroscopic experiments on 20-module superstructures, each featuring two Ge wells coupled through a Ge-rich SiGe tunnel barrier, as a function of the geometry parameters of the design and the P dopant concentration. Through a comparison of THz spectroscopic data with numerical calculations of intersubband optical absorption resonances, we demonstrated that it is possible to tune, by design, the energy and the spatial overlap of quantum confined subbands in the conduction band of the heterostructures. The high structural/interface quality of the samples and the control achieved on subband hybridization are promising starting points towards a working electrically pumped light-emitting device.

High-efficiency near-UV light-emitting diodes on Si substrates with InGaN/GaN/AlGaN/GaN multiple quantum wells

2020 ◽  
Vol 8 (3) ◽  
pp. 883-888 ◽  
Author(s):  
Yuan Li ◽  
Zhiheng Xing ◽  
Yulin Zheng ◽  
Xin Tang ◽  
Wentong Xie ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantum Efficiency ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Uv Light ◽  
Multiple Quantum ◽  
High Quantum Efficiency ◽  
Light Emitting ◽  
Si Substrates

High quantum efficiency LEDs with InGaN/GaN/AlGaN/GaN MQWs have been demonstrated. The proposed GaN interlayer barrier can not only increase the concentration and the spatial overlap of carriers, but also improve the quality of the MQWs.

Comparative Study of GaN—Based LED Grown on Different Substrates

2011 ◽  
Vol 194-196 ◽  
pp. 2241-2244
Author(s):  
Dong Sheng Peng ◽  
Ke Jin ◽  
Rui Sheng Zheng ◽  
Lei Liu ◽  
Zhe Chuan Feng
Keyword(s):  
Quantum Wells ◽  
Sapphire Substrate ◽  
Silicon Substrate ◽  
Chemical Vapor ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Light Emitting ◽  
Crystal Properties

The InGaN/GaN multiple quantum wells (MQWs) light emitting diodes (LEDs) were grown by metalorganic chemical vapor deposition (MOCVD) on silicon and sapphire substrates, respectively. The Optical and crystal properties of InGaN/GaN MQWs LEDs were investigated by room temperature photoluminescence (PL), temperature dependent PL measurements, Raman spectra and high-resolution double crystal X-ray diffraction(DCXRD). These results indicate that the crystal quality of InGaN/GaN MQWs growth on sapphire substrate are more preferable than that of InGaN/GaN MQWs growth on silicon substrate, and the interface of MQWs growth on substrate or silicon substrate is level. The peak positions of InGaN/GaN MQWs are 2.78 eV (446nm) and 2.64 eV (468.8nm) growth on sapphire substrate and silicon substrate, respectively.

scholarly journals Reduction of efficiency droop in InGaN light emitting diodes by coupled quantum wells

2008 ◽  
Vol 93 (17) ◽  
pp. 171113 ◽  
Author(s):  
Xianfeng Ni ◽  
Qian Fan ◽  
Ryoko Shimada ◽  
Ümit Özgür ◽  
Hadis Morkoç
Keyword(s):  
Quantum Wells ◽  
Light Emitting Diodes ◽  
Efficiency Droop ◽  
Coupled Quantum Wells ◽  
Light Emitting

Comparative investigation of the interface quality of quantum wells grown by MBE

1990 ◽  
Vol 8 (2) ◽  
pp. 183-186 ◽  
Author(s):  
T. Schweizer ◽  
K. Köhler ◽  
J. Wagner ◽  
P. Ganser ◽  
M. Maier ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Comparative Investigation ◽  
Interface Quality

scholarly journals Effect of Same-Temperature GaN Cap Layer on the InGaN/GaN Multiquantum Well of Green Light-Emitting Diode on Silicon Substrate

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Changda Zheng ◽  
Li Wang ◽  
Chunlan Mo ◽  
Wenqing Fang ◽  
Fengyi Jiang
Keyword(s):  
Quantum Wells ◽  
Light Emitting Diode ◽  
Green Light ◽  
Xrd Analysis ◽  
Light Emitting ◽  
Green Led ◽  
Cap Layer ◽  
Different Thickness ◽  
Ingan Quantum Wells

GaN green LED was grown on Si (111) substrate by MOCVD. To enhance the quality of InGaN/GaN MQWs, same-temperature (ST) GaN protection layers with different thickness of 8 Å, 15 Å, and 30 Å were induced after the InGaN quantum wells (QWs) layer. Results show that a relative thicker cap layer is benefit to get InGaN QWs with higher In percent at fixed well temperature and obtain better QW/QB interface. As the cap thickness increases, the indium distribution becomes homogeneous as verified by fluorescence microscope (FLM). The interface of MQWs turns to be abrupt from XRD analysis. The intensity of photoluminescence (PL) spectrum is increased and the FWHM becomes narrow.

scholarly journals Quantum cascade light-emitting diodes based on type-II quantum wells

1997 ◽  
Author(s):  
C.H. T. Lin ◽  
Rui Q. Yang ◽  
Dongxu Zhang ◽  
Stefan J. Murry ◽  
Shin Shem Pei ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Light Emitting Diodes ◽  
Type Ii ◽  
Light Emitting ◽  
Quantum Cascade ◽  
Type Ii Quantum Wells

InGaPN/GaP Lattice-Matched Single Quantum Wells on GaP (001) Grown by MOVPE

2008 ◽  
Vol 55-57 ◽  
pp. 821-824 ◽  
Author(s):  
D. Kaewket ◽  
S. Sanorpim ◽  
Sukkaneste Tungasmita ◽  
R. Katayama ◽  
Kentaro Onabe
Keyword(s):  
Quantum Wells ◽  
Conduction Band ◽  
Light Emission ◽  
Peak Position ◽  
Conduction Band Edge ◽  
Single Quantum ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
Conduction Band Offset ◽  
Lattice Matched

Highly luminescence lattice-matched InxGa1-xP1-yNy/GaP single quantum wells (SQWs) on GaP (001) substrates were successfully grown by metalorganic vapor phase epitaxy (MOVPE). High-resolution X-ray diffraction measurements established that the lattice-matched InxGa1-xP1-yNy/GaP SQWs with various In (x = 0.050, 0.080, 0.135) and N (y = 0.025, 0.048, 0.071) contents were realized with excellent crystal quality and fairly flat interfaces. The results of photoluminescence (PL) and PL-excitation (PLE) showed the strong visible light emission (yellow to red emission) from the SQWs. With increasing In and N contents, the PL peak position and the PLE absorption edge exhibited the red-shift to lower energy, indicating the lowering of the InGaPN conduction band edge. The conduction band offset (∆Ec) of the InGaAPN/GaP quantum structure was estimated to be as high as 270 to 480 meV, which depends on the In and N contents in the well. Our results demonstrate that this novel InGaPN/GaP SQW system appropriates for the fabrication of light-emitting and laser diodes.

Light-emitting properties of a strain-tuned microtube containing coupled quantum wells

2013 ◽  
Vol 102 (4) ◽  
pp. 041109 ◽  
Author(s):  
S. Kiravittaya ◽  
Ch. Deneke ◽  
Dominic J. Thurmer ◽  
O. G. Schmidt
Keyword(s):  
Quantum Wells ◽  
Coupled Quantum Wells ◽  
Light Emitting
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