Analysis of EL Emitted by LEDs on Si Substrates Containing GeSn/Ge Multi Quantum Wells as Active Layers

2015 ◽  
Vol 242 ◽  
pp. 361-367 ◽  
Author(s):  
Bernhard Schwartz ◽  
Philipp Saring ◽  
Tzanimir Arguirov ◽  
Michael Oehme ◽  
Konrad Kostecki ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Heavy Hole ◽  
Compressive Strain ◽  
Threading Dislocation ◽  
Light Emitting ◽  
Si Substrates ◽  
Active Layers ◽  
Hole Band ◽  
Threading Dislocation Density ◽  
Multi Quantum Well

We analyzed multi quantum well light emitting diodes, consisting of ten alternating GeSn/Ge-layers, were grown by molecular beam epitaxy on Si. The Ge barriers were 10 nm thick and the GeSn wells were grown with 7% Sn and thicknesses between 6 and 12 nm. Despite the high threading dislocation density of 109to 1010cm−2the electroluminescence spectra measured at 300 and 80 K yield a broad and intensive luminescence band. Deconvolution revealed three major lines produced by the GeSn wells that can be interpreted in terms of quantum confinement. Biaxial compressive strain causes a splitting of light and heavy holes in the GeSn wells. We interpret the three lines to represent two direct lines, formed by transitions with the light and heavy hole band, respectively, andan indirect line.

High Efficiency Uv Emitter Using High Quality GaN/AlxGa1−xN Multi-Quantum Well Active Layer

2000 ◽  
Vol 639 ◽  
Author(s):  
M. Iwaya ◽  
S. Terao ◽  
T. Ukai ◽  
R. Nakamura ◽  
S. Kamiyama ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Quantum Wells ◽  
High Efficiency ◽  
Light Emitting Diode ◽  
Threading Dislocation ◽  
Light Emitting ◽  
Si Doping ◽  
Threading Dislocation Density ◽  
Pl Intensity ◽  
Multi Quantum Well

ABSTRACTWe investigated temperature dependence of the photoluminescence (PL) efficiency of GaN/Al0.08Ga0.92N multi-quantum wells (MQWs) with variations of Si-doping condition and threading dislocation density. Si-doping in the GaN/Al0.08Ga0.92N MQWs, especially in the barrier layer improves the PL efficiency. In addition, reduction of threading dislocation density also improves the PL intensity. The PL intensity of the GaN/Al0.08Ga0.92N MQW is drastically increased at least by a factor of 40, by a combination of the Si-doping and reduction of threading dislocation density. We fabricated a light emitting diode (LED) emitting at 357 nm using such a GaN/Al0.08Ga0.92N MQWs. Electro-luminescence intensity from the region with threading dislocation density of less than 108 cm−2 was much larger than that from the region with threading dislocation density of 6×109 cm−2.

High quality AlN with uniform in-plane strain on nano-patterned AlN templates achieved by preset strain modulation

2021 ◽  
Author(s):  
Baiyin Liu ◽  
Fujun Xu ◽  
Jiaming Wang ◽  
Jing Lang ◽  
Na Zhang ◽  
...  
Keyword(s):  
Plane Strain ◽  
Light Emitting Diode ◽  
Compressive Strain ◽  
Light Output ◽  
Threading Dislocation ◽  
High Quality ◽  
Light Emitting ◽  
Threading Dislocation Density ◽  
Strain Modulation ◽  
Single Emission

Abstract High-quality AlN with uniform in-plane strain has been attempted with preset strain modulation on nano-patterned AlN templates (NPATs). It is found that this strain preset frame can effectively improve both the tilt and twist features of AlN on NPATs, further greatly decreasing threading dislocation density. More importantly, the AlN epilayer after completing coalescence can maintain the in-plane uniform compressive strain. Adopting AlN templates achieved in this scheme, the chip-on-wafer light output power (LOP) of AlGaN light-emitting diode (LED) reaches 10.2 mW at 100 mA with single emission peak at 280 nm, which increases by 22.3% than the LOP of LED device without adopting this strain preset frame.

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.

MO-CVD GaAs Grown by Direct Deposition on Si

1987 ◽  
Vol 91 ◽  
Author(s):  
S. M. Vernon ◽  
S. J. Pearton ◽  
J. M. Gibson ◽  
R. Caruso ◽  
C. R. Abernathy ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Gaas Layer ◽  
Threading Dislocation ◽  
X Ray Diffraction ◽  
Si Substrates ◽  
Transmission Electron ◽  
Activation Data ◽  
Threading Dislocation Density ◽  
Donor Activity

ABSTRACTGaAs layers were grown directly on misoriented (2° off (100)→[011]) Si substrates by Metalorganic Chemical Vapor Deposition. The threading dislocation density at the surface of 4 μm thick layers was typically 108cm−2, as determined by both preferential etching and transmission electron microscopy. Rapid thermal annealing (900°C, 10s) improved the crystalline quality of the GaAs near the heterointerface while allowing no detectable Si diffusion into this layer. Two deep electron traps were observed in the undoped GaAs, but were present at a low concentration (∼ 1013 cm−3 ). The (400) x-ray diffraction peak width from the GaAs was significantly reduced with increasing GaAs layer thickness, indicating improved material quality. This is supported by Si implant activation data, which shows higher net donor activity in thicker layers.

The Heteroepitaxy and Characterization of Inp and GaInP on Silicon for Solar Cell Applications

1990 ◽  
Vol 198 ◽  
Author(s):  
M.M. Al-Jassim ◽  
R.K. Ahrenkiel ◽  
M.W. Wanlass ◽  
J.M. Olson ◽  
S.M. Vernon
Keyword(s):  
Carrier Lifetime ◽  
Minority Carrier ◽  
Defect Density ◽  
Minority Carrier Lifetime ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Si Substrates ◽  
Threading Dislocation Density ◽  
Direct Growth

ABSTRACTInP and GaInP layers were heteroepitaxially grown on (100) Si substrates by atmospheric pressure MOCVD. TEM and photoluminescence (PL) were used to measure the defect density and the minority carrier lifetime in these structures. The direct growth of InP on Si resulted in either polycrystalline or heavily faulted single-crystal layers. The use of GaAs buffer layers in InP/Si structures gave rise to significantly improved morphology and reduced the threading dislocation density. The best InP/Si layers in this study were obtained by using GaAs-GaInAs graded buffers. Additionally, the growth of high quality GaInP on Si was demonstrated. The minority carrier lifetime of 7 ns in these layers is the highest of any III-V/Si semiconductor measured in our laboratory.

Details of the improvement of crystalline quality of a-plane GaN using one-step lateral growth

2006 ◽  
Vol 955 ◽  
Author(s):  
Daisuke Iida ◽  
Tetsuya Nagai ◽  
Takeshi Kawashima ◽  
Aya Miura ◽  
Yoshizane Okadome ◽  
...  
Keyword(s):  
Defect Density ◽  
Light Output ◽  
Epitaxial Lateral Overgrowth ◽  
Root Mean Square Roughness ◽  
Threading Dislocation ◽  
Light Emitting ◽  
Lateral Overgrowth ◽  
Green Led ◽  
Threading Dislocation Density ◽  
One Step

ABSTRACTLow defect density a-plane GaN films were successfully grown by sidewall epitaxial lateral overgrowth (SELO) technique. Control of V/III ratio during the growth of GaN by metalorganic vapor phase epitaxy (MOVPE) was found to be very important to achieve a complete overgrowth on the SiO2 mask regions and atomically flat surface. The threading dislocation and stacking fault densities in the overgrown regions were lower than 106 cm−2 and 103 cm−1, respectively. The root mean square roughness was 0.09 nm. We also fabricated and characterized a-plane-GaN-based-light-emitting diodes (LEDs) using SELO technique. The light output power of the blue-green LED steeply increased with the decrease of threading dislocation density from 1010 cm−2 to 108 cm−2 and tended to saturate at lower dislocation densities.

The Influence of Substrate Patterning on Threading Dislocation Density and Residual Stress in GaAs/Si Heteroepitaxial Layers.

1990 ◽  
Vol 198 ◽  
Author(s):  
Hyunchul Sohn ◽  
Eicke R. Weber ◽  
Jay Tu ◽  
Henry P. Lee ◽  
Shy Wang
Keyword(s):  
Residual Stress ◽  
Dislocation Density ◽  
Threading Dislocation ◽  
Etch Pits ◽  
Cross Sectional ◽  
Strained Layers ◽  
Si Substrates ◽  
Growth Area ◽  
Threading Dislocation Density ◽  
Influence Of Substrate

ABSTRACTThe growth of GaAs films by MBE on mesa-type patterned Si substrates has been investigated. Mesa widths were varied from 10 µm to 200 µm and were prepared using chemical etching with Si3N4 masks and reactive ion etching. The residual stress in the epitaxial layer was estimated using low temperature (7K) photoluminescence and the defect distribution was studied by cross sectional TEM, dislocation densities were in addition determined by etch pits. The residual stress and the dislocation density decreased monotonically with the reduction of growth area. By the incorporation of strained layers with the reduction of growth area, the etch pit density in GaAs layers on mesas was reduced further.

Photoluminescence Study of GaAs/AlGaAs Quantum Wells Grown On Si Substrates

1987 ◽  
Vol 91 ◽  
Author(s):  
C. Jagannath ◽  
S. Zemon ◽  
P. Norris ◽  
B.S. Elman ◽  
S.K. Shastry
Keyword(s):  
Quantum Wells ◽  
Heavy Hole ◽  
Biaxial Tension ◽  
Light Hole ◽  
Experimental Results ◽  
Photoluminescence Excitation ◽  
Exciton Energy ◽  
Photoluminescence Study ◽  
Si Substrates ◽  
Gaas Substrates

ABSTRACTPhotoluminescence and photoluminescence excitation spectroscopies are utilized to study excitons in GaAs/AlGaAs quantum wells (QW's) fabricated using MBE on MOCVD grown GaAs/Si. The experimental results are understood in terms of the biaxial tension of approximately 3 kbar present in the plane of growth for both the QW's and the GaAs buffer. An important consequence of the biaxial tension is that for QW's with well widths larger than ≈15 nm the light- and heavy- hole sub-bands cross each other in energy. This results in the light-hole exciton energy being lower than that of the heavy-hole exciton, opposite to the case of QW's grown on GaAs substrates.

Sign in / Sign up

Export Citation Format

Share Document