Optical and crystal quality improvement in green emitting InxGa1-xN multi-quantum wells through optimization of MOCVD growth

2016 ◽  
Author(s):  
Erkan A. Berkman ◽  
Soo Min Lee ◽  
Frank Ramos ◽  
Eric Tucker ◽  
Ronald A. Arif ◽  
...  
Keyword(s):  
Quality Improvement ◽  
Quantum Wells ◽  
Crystal Quality ◽  
Mocvd Growth

scholarly journals Enhancement of quantum efficiency in InGaN quantum wells by using superlattice interlayers and pulsed growth

2016 ◽  
Vol 55 (4) ◽  
Author(s):  
Kazimieras Nomeika ◽  
Mantas Dmukauskas ◽  
Ramūnas Aleksiejūnas ◽  
Patrik Ščajev ◽  
Saulius Miasojedovas ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantum Efficiency ◽  
Light Emitting Diode ◽  
Internal Quantum Efficiency ◽  
Recombination Coefficient ◽  
Time Resolved ◽  
Mocvd Growth ◽  
Lower Strain ◽  
Type Contact ◽  
Ingan Quantum Wells

Enhancement of internal quantum efficiency (IQE) in InGaN quantum wells by insertion of a superlattice interlayer and applying the pulsed growth regime is investigated by a set of time-resolved optical techniques. A threefold IQE increase was achieved in the structure with the superlattice. It was ascribed to the net effect of decreased internal electrical field due to lower strain and altered carrier localization conditions. Pulsed MOCVD growth also resulted in twice higher IQE, presumably due to better control of defects in the structure. An LED (light emitting diode) structure with a top p-type contact GaN layer was manufactured by using both growth techniques with the peak IQE equal to that in the underlying quantum well structure. The linear recombination coefficient was found to gradually increase with excitation due to carrier delocalization, and the latter dependence was successfully used to fit the IQE droop.

Crystal Quality Improvement of α-Ga2O3 Growth on Stripe Patterned Template via Epitaxial Lateral Overgrowth

2019 ◽  
Vol 19 (9) ◽  
pp. 5105-5110 ◽  
Author(s):  
Hoki Son ◽  
Ye-ji Choi ◽  
Jun-Seok Ha ◽  
Sung Hoon Jung ◽  
Dae-Woo Jeon
Keyword(s):  
Quality Improvement ◽  
Crystal Quality ◽  
Epitaxial Lateral Overgrowth ◽  
Lateral Overgrowth

Post and In Situ Characterization of Strain Control and Crystal Quality in Quantum Well Solar Cell Structure

2011 ◽  
Vol 675-677 ◽  
pp. 73-76
Author(s):  
Yun Peng Wang ◽  
Momoko Deura ◽  
Masakazu Sugiyama ◽  
Yoshiaki Nakano
Keyword(s):  
Solar Cell ◽  
Quantum Wells ◽  
Cell Structure ◽  
Lattice Relaxation ◽  
Crystal Quality ◽  
Multiple Quantum ◽  
Average Strain ◽  
Reflectivity Measurement ◽  
Surface Reflectivity

To improve current matching in a tandem solar cell, a strain-compensated InGaAs/GaAsP multiple quantum-wells (MQWs) structure was grown within the middle GaAs PN junction, using metal organic vapor phase epitaxy (MOVPE) on GaAs substrate. Aiming at an accurate design of adsorption edge and precise control of crystal quality in MQWs, post- and in situ characterization was applied in such a fabrication process. Here, we report some applications of some post-characterization such as: X-ray scanning and reciprocal mapping in clarifying composition and crystal quality in these structures; photoluminescence (PL) and FTIR in determining adsorption edge and even indicate some irradiative recombination features as well. By employing an in situ optical surface reflectivity measurement, we established a way of and evaluating an instant of strain relaxation in the course of MOVPE, which deteriorates crystal quality significantly. When strain balancing was incomplete, surface reflectivity dropped during the growth of MQWs, indicating lattice relaxation. The accumulated strain, which is defined as the average strain per period of QW multiply the number of stacking for MQWs , was roughly constant for all the MQWs samples in our experiment. Therefore, it may indicate that this overall strain may be used as a tentative criterion of critical value for lattice relaxation or to predict the maximum number of MQWs for a given value of the average strain per QW period. Combining both post and in situ characterizations, we can effectively adjust the overall strain to get defects free growth for MQWs, and also significant features can be observed for better understanding the heterostructure management.

Improvements of Structural and Optical Properties of GaN/Al0.10Ga0.9N Multi-Quantum Wells by Isoelectronic In-doping

2001 ◽  
Vol 693 ◽  
Author(s):  
Lianshan Wang ◽  
Soo Jin Chua ◽  
Wenhong Sun
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Chemical Deposition ◽  
Crystal Quality ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Flow Rates ◽  
X Ray ◽  
In Doping ◽  
Metalorganic Chemical

Absratct:The effects of isoelectronic In-doping were studied on the structural and optical properties of 3-periods and 10-periods of GaN/Al0.10Ga0.90N multi quantum wells (MQWs). The GaN/Al40.10Ga0.90N MQWs were grown on u-GaN/sapphire via metalorganic chemical deposition (MOCVD) at 1050°C in H2 carrier gas. X-ray diffraction (XRD), and micro-Photoluminescence (PL) measurements revealed that In-doping into well layers improves the crystalline and optical properties of MQWs relative to those samples without In-doping. With increasing Trimethylindium (TMIn) flow rates from 4.2 mol/min to 42.6 mol/min, PL peaks from well layers obviously redshifted, due to the improvement of the strain along the interfaces between MQWS, irrespective of 3-periods or 10 periods MQWs. The improvement of the crystal quality was also confirmed by XRD.

LP-MOCVD growth and characterization of undoped and modulation doped GaInAsP/InP and GaInAs/InP multi quantum wells

1988 ◽  
Vol 93 (1-4) ◽  
pp. 382-388 ◽  
Author(s):  
D. Grützmacher ◽  
R. Meyer ◽  
M. Zachau ◽  
P. Helgesen ◽  
A. Zrenner ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Mocvd Growth
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