Advantages of the moth-eye patterned sapphire substrate for the high performance nitride based LEDs

2014 ◽  
Vol 11 (3-4) ◽  
pp. 771-774 ◽  
Author(s):  
Toshiyuki Kondo ◽  
Tsukasa Kitano ◽  
Atsushi Suzuki ◽  
Midori Mori ◽  
Koichi Naniwae ◽  
...  
Keyword(s):  
Sapphire Substrate ◽  
High Performance ◽  
Patterned Sapphire Substrate

High-Performance GaN-Based Light-Emitting Diodes on Patterned Sapphire Substrate with a Novel Patterned SiO2/Al2O3Passivation Layer

2013 ◽  
Vol 6 (7) ◽  
pp. 072103 ◽  
Author(s):  
Hao Guo ◽  
Xiong Zhang ◽  
Hongjun Chen ◽  
Honggang Liu ◽  
Peiyuan Zhang ◽  
...  
Keyword(s):  
Sapphire Substrate ◽  
High Performance ◽  
Light Emitting Diodes ◽  
Patterned Sapphire Substrate ◽  
Light Emitting

Implementation of a High-Performance GaN-Based Light-Emitting Diode Grown on a Nanocomb-Shaped Patterned Sapphire Substrate

2014 ◽  
Vol 50 (12) ◽  
pp. 973-980 ◽  
Author(s):  
Jian-Kai Liou ◽  
Chun-Chia Chen ◽  
Po-Cheng Chou ◽  
Zong-Jie Tsai ◽  
Yu-Chih Chang ◽  
...  
Keyword(s):  
Sapphire Substrate ◽  
High Performance ◽  
Light Emitting Diode ◽  
Patterned Sapphire Substrate ◽  
Light Emitting

scholarly journals Reduction of dislocations in α-Ga2O3 epilayers grown by halide vapor-phase epitaxy on a conical frustum-patterned sapphire substrate

IUCrJ ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 462-467
Author(s):  
Hoki Son ◽  
Ye-ji Choi ◽  
Soon-Ku Hong ◽  
Ji-Hyeon Park ◽  
Dae-Woo Jeon
Keyword(s):  
Vapor Phase ◽  
Sapphire Substrate ◽  
High Performance ◽  
Lattice Mismatch ◽  
Vapor Phase Epitaxy ◽  
Stress Generation ◽  
Threading Dislocation ◽  
High Quality ◽  
Patterned Sapphire Substrate ◽  
Patterned Substrate

The compound α-Ga2O3 is an ultra-wide-bandgap semiconductor and possesses outstanding properties such as a high breakdown voltage and symmetry compared with other phases. It has been studied for applications in high-performance power devices. However, it is difficult to obtain a high-quality thin films because α-Ga2O3 can only grow heteroepitaxially, which results in residual stress generation owing to lattice mismatch and thermal expansion between the substrate and α-Ga2O3. To overcome this, α-Ga2O3 was grown on a conical frustum-patterned sapphire substrate by halide vapor-phase epitaxy. The surface morphology was crack-free and flat. The α-Ga2O3 grown on a frustum-patterned substrate and a conventional sapphire substrate at 500°C exhibited full-width at half-maxima of 961 and 1539 arcsec, respectively, for 10–12 diffraction. For the former substrate, lateral growth on the pattern and threading dislocation bending towards the pattern suppressed the propagation of threading dislocations generated at the interface, which reduced the threading dislocation propagation to the surface by half compared with that on the latter conventional substrate. The results suggest that conical frustum-patterned sapphire substrates have the potential to produce high-quality α-Ga2O3 epilayers.

scholarly journals Temperature Dependence of Stress and Optical Properties in AlN Films Grown by MOCVD

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 698
Author(s):  
Wenwang Wei ◽  
Yi Peng ◽  
Jiabin Wang ◽  
Muhammad Farooq Saleem ◽  
Wen Wang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Compressive Stress ◽  
Sapphire Substrate ◽  
Light Transmission ◽  
Chemical Vapor ◽  
Biaxial Stress ◽  
X Ray Diffraction ◽  
Patterned Sapphire Substrate ◽  
Transmission Electron ◽  
Nano Patterning

AlN epilayers were grown on a 2-inch [0001] conventional flat sapphire substrate (CSS) and a nano-patterned sapphire substrate (NPSS) by metalorganic chemical vapor deposition. In this work, the effect of the substrate template and temperature on stress and optical properties of AlN films has been studied by using Raman spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-visible spectrophotometer and spectroscopic ellipsometry (SE). The AlN on NPSS exhibits lower compressive stress and strain values. The biaxial stress decreases from 1.59 to 0.60 GPa for AlN on CSS and from 0.90 to 0.38 GPa for AlN on NPSS sample in the temperature range 80–300 K, which shows compressive stress. According to the TEM data, the stress varies from tensile on the interface to compressive on the surface. It can be deduced that the nano-holes provide more channels for stress relaxation. Nano-patterning leads to a lower degree of disorder and stress/strain relaxes by the formation of the nano-hole structure between the interface of AlN epilayers and the substrate. The low crystal disorder and defects in the AlN on NPSS is confirmed by the small Urbach energy values. The variation in bandgap (Eg) and optical constants (n, k) with temperature are discussed in detail. Nano-patterning leads to poor light transmission due to light scattering, coupling, and trapping in nano-holes.

Demonstration of GaN-based white LED grown on 4-inch patterned sapphire substrate by MOCVD

2021 ◽  
Vol 112 ◽  
pp. 110811
Author(s):  
Youhua Zhu ◽  
Xuan Liu ◽  
Mei Ge ◽  
Yi Li ◽  
Meiyu Wang
Keyword(s):  
Sapphire Substrate ◽  
White Led ◽  
Patterned Sapphire Substrate
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