Browsing by Author "Yu, Wen-Chien"

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Enhanced solar-light transmission by broadband anti-reflective structure with mesoporous silica of low refractive index
(2008)
Wang, Chao-Kei
;
Shieh, Jia-Min
;
Wu, Shich-Chuan
;
Yu, Wen-Chien
;
Kuo, Hao-Chung
Mesoporus silica dielectrics, which revealed low refractive index (n similar to 1.26), were introduced together with Si3N4 layers to be double-layer-based graded-refractive-index ant-reflectors for silicon solar-cells. Enhanced solar-light transmission increased conversion efficiency of Si solar panels by 4%.
Formation of nitride laser cavities with cleaved facets on transferred laser diodes on GaAs substrates
(2008)
Yu, Wen-Chien
;
Ye, Shu-Mei
;
Hsiao, Feng-Ke
;
Lee, Chi-Ling
;
Lee, Wei-I
Smoothly cleaved facets with high reflectivities have been demonstrated on GaN laser diodes after the devices were transferred onto GaAs substrates. The GaN based laser diode structure was first fabricated by metal organic chemical vapor deposition (MOCVD) on c-plane sapphire substrates. The samples were then mounted onto thin GaAs substrates using wafer-bonding technology. Laser lift-off (LLO) technique was applied to remove the original sapphire substrate and transfer the GaN laser structure onto GaAs substrates. Since the cubic substrates have well-defined laser cavity cleavage facet, the GaN structures bonded onto the substrates also formed smooth facets after cleavage. The cleaved facets of GaN laser diodes have been characterized using atomic force microscopy (AFM) with less than 2 nm roughness. The present study demonstrated the feasibility of transferring GaN laser structures onto other more appealing substrates for formation of laser cavities.
Near Infrared Silicon Quantum Dots MOSFET Detector
(2009-01-01)
Shieh, Jia-Min
;
Yu, Wen-Chien
;
Wang, Chao-Kei
;
Dai, Bau-Tong
;
Kuo, Hao-Chung
Fully Si-based MOSFET photodetector was demonstrated at optical telecommunication wavelengths by using a gate dielectric stack comprising of a Si quantum dots film. Illumination at wavelengths lambda=1.55 mu m, photoresponse as high as 2.0A/W was measured. (C) 2009 Optical Society of America
Near-infrared silicon quantum dots metal-oxide-semiconductor field-effect transistor photodetector
(2009-06-15)
Shieh, Jia-Min
;
Yu, Wen-Chien
;
Huang, Jung Y.
;
Wang, Chao-Kei
;
Dai, Bau-Tong
A fully silicon-based metal-oxide-semiconductor field-effect transistor is demonstrated for the detection of near-infrared light. Si nanocrystals (nc-Si) are synthesized in the nanopore channels of mesoporous silica (MS) inserted between two oxide layers to form a complete gate structure of polycrystalline Si/SiO(2)/nc-Si-in-MS/SiO(2) with a polycrystalline Si electrode. Illuminating the gate with near-infrared light, a photoresponsivity as high as 2.8 A/W at 1.55 mu m can be achieved. The improved photoresponsivity is attributed to from optical transitions via interface states and a current amplification mechanism of the device.
Nonvolatile memory with switching interfacial polar structures of nano Si-in-mesoporous silica
(2009-10-05)
Shieh, Jia-Min
;
Huang, Jung Y.
;
Yu, Wen-Chien
;
Huang, Jian-Da
;
Wang, Yi-Chao
We show an artificially engineered electret with Si nanocrystals embedded in mesoporous silica for nonvolatile memory. We attribute the polarization to from polar layers lying at the interfaces between one-side bonded Si nanocrystals and mesoporous silica matrix. Under external field, the Si nanocrystals could be displaced in the porechannels causing displaced charge distributions and therefore a field-controllable electric polarization. Nonvolatile memory is demonstrated with a metal-oxide-semiconductor field-effect transistor. (C) 2009 American Institute of Physics. [doi:10.1063/1.3240888]
Optical sum-frequency generation and Ferroelectric-like Switching in Si-O Polar Structures
(2009-01-01)
Shieh, Jia-Min
;
Yu, Wen-Chien
;
Huang, Jung Y.
;
Wang, Yi-Chao
;
Chen, Ching-Wei
Optical sum-frequency generation and ferroelectric-like switching in Si-O polar structures comprised of Si nanocrystals (nc-Si) in mesoporous silica was reported and attributed to polar layers lying at the interfaces between one-side bonded nc-Si and host. (C) 2009 Optical Society of America
Thin Film Silicon Solar Cell Fabricated at 100 degrees C by High Density Plasma for Flexible Photovoltaic Application
(2010-01-01)
Shen, Chang-Hong
;
Shieh, Jia-Min
;
Kuo, Hao-Chung
;
Huang, Jung Y.
;
Yu, Wen-Chien
Record fabrication temperature, 100 degrees C, of a single junction amorphous Si solar cell was demonstrated by a high-density plasma method. Present solar cell revealed conversion efficiency of 7.4% at 200 degrees C (4.1% at 135 degrees C). (C) 2009 Optical Society of America