Browsing by Author "Wu, Y. S."

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Bandwidth enhancement phenomenon of a high-speed GaAs-AlGaAs based unitraveling carrier photodiode with an optimally designed absorption layer at an 830 nm wavelength
(2006-07-31)
Shi, Jin-Wei
;
Li, Yu-Tai
;
Pan, Ci-Ling
;
Lin, M. L.
;
Wu, Y. S.
In this letter, the authors introduce a GaAs/AlGaAs based unitraveling carrier photodiode (UTC-PD) for a wavelength of around 830 nm. There is significant bias- and output-current-dependent bandwidth enhancement phenomena observed with this device. According to their microwave and optical-to-electrical measurement results, such distinct phenomena can occur under a much lower current density (0.3 mA/mu m(2) vs 0.05 mA/mu m(2)) than previously reported for InP-InGaAs UTC-PDs. This can be attributed to the self-induced field in the absorption region, made possible due to the optimized p-type doping profile. (c) 2006 American Institute of Physics.
Enhancement Performance of GaN-based Light-emitting Diodes by Modified Patterned Sapphire Surface
(2010)
Lin, B-W.
;
Hsu, W-C.
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Wu, Y. S.
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材料科學與工程學系
;
Department of Materials Science and Engineering
The PSSs were fabricated by wet etching. Compared with the platform-PSS, the modified-PSS was still capped with a layer on the top platform after wet etching. The output power of the platform-PSS LED and modified-PSS are 27.3 mW and 29 mW, respectively, at an injection current of 20 mA. The output power of the modified-PSS LED is enhanced 6% compared with the platform-PSS. The results reveal that both electrical properties and optical properties of modified-PSS LED were improved.
High performance poly-Si TFTs fabricated by continuous-wave laser annealing of metal-induced lateral crystallised silicon films
(2008-09-11)
Chang, C. -P.
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Wu, Y. S.
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材料科學與工程學系
;
Department of Materials Science and Engineering
In this process, amorphous silicon was first transformed to polycrystalline silicon (poly-Si) using a metal-induced lateral crystallisation (MILC) process, followed by annealing with a continuous-wave laser lateral (lambda similar to 532 nm) crystallisation (CLC) with an output power of 3.8 W. MILC-CLC-TFT performed far superior to MILC-TFT. The mobility of the MILC-CLC-TFT was 293 cm(2)/Vs, which was much higher than that of MILC TFTs (54.8 cm(2)/Vs). In addition, MILC-CLC TFTs showed better device uniformity and reliability.
Interface morphology and electrical properties of bonded GaAs/GaAs wafers at different temperatures
(2012)
Chang, S. C.
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Wu, Y. S.
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Chang, N.
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材料科學與工程學系
;
Department of Materials Science and Engineering
The microstructure and electrical properties of p-GaAs/n-GaAs bonded interface were investigated. It was observed that when bonding temperature increased from 600 to 800 degrees C, the thickness of oxide layer decreased. Current-voltage characteristic shows typical diode behaviors in these temperature ranges.
The Formation of The Hexagonal Pyramid Facets on Wet Etching Patterned Sapphire Substrate
(2013)
Chen, Y. C.
;
Hsiao, F. C.
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Wu, Y. S.
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Currently, the wet etching patterned sapphire substrate (PSS) has attracted much attention for its high production yield. After etching in hot mixed H2SO4 and H3PO4 solution, the several etched facets were exposed on sapphire substrate. In this study, a series of etching process was used to investigate the formation. As shown in Fig. 1, when SiO2 mask still remained, the structure of PSS comprised of six facets {3 (4) over bar 17}. When SiO2 mask were etched away, beside six facets, there were three extra facets {1 (1) over bar 05} exposed on the top.