學術出版;;Publications

Permanent URI for this communityhdl:11536/1

收集所有交通大學研究人員與學生個人或團體所發表之各項學術著作，涵蓋期刊論文、教師專書、學位論文等項。;;Collections of Publications of NCTU Researchers and Students Like Journal Papers and Thesis.

Browse

🏛️國立陽明交通大學機構典藏

Search Results

Now showing 1 - 8 of 8

Silicon Nanowires for Solar Thermal Energy Harvesting: an Experimental Evaluation on the Trade-off Effects of the Spectral Optical Properties
(2016-01-04)
Sekone, Abdoul Karim
;
Chen, Yu-Bin
;
Lu, Ming-Chang
;
Chen, Wen-Kai
;
Liu, Chia-An
Silicon nanowire possesses great potential as the material for renewable energy harvesting and conversion. The significantly reduced spectral reflectivity of silicon nanowire to visible light makes it even more attractive in solar energy applications. However, the benefit of its use for solar thermal energy harvesting remains to be investigated and has so far not been clearly reported. The purpose of this study is to provide practical information and insight into the performance of silicon nanowires in solar thermal energy conversion systems. Spectral hemispherical reflectivity and transmissivity of the black silicon nanowire array on silicon wafer substrate were measured. It was observed that the reflectivity is lower in the visible range but higher in the infrared range compared to the plain silicon wafer. A drying experiment and a theoretical calculation were carried out to directly evaluate the effects of the trade-off between scattering properties at different wavelengths. It is clearly seen that silicon nanowires can improve the solar thermal energy harnessing. The results showed that a 17.8 % increase in the harvest and utilization of solar thermal energy could be achieved using a silicon nanowire array on silicon substrate as compared to that obtained with a plain silicon wafer.
Absorption enhancement in type-II coupled quantum rings due to existence of quasi-bound states
(2018-01-01)
Hsieh, Chi-Ti
;
Lin, Shih-Yen
;
Chang, Shu-Wei
;
光電工程學系
;
Department of Photonics
The absorption of type-II nanostructures is often weaker than type-I counterpart due to spatially separated electrons and holes. We model the bound-to-continuum absorption of type-II quantum rings (QRs) using a multiband source-radiation approach using the retarded Green function in the cylindrical coordinate system. The selection rules due to the circular symmetry for allowed transitions of absorption are utilized. The bound-to continuum absorptions of type-II GaSb coupled and uncoupled QRs embedded in GaAs matrix are compared here. The GaSb QRs act as energy barriers for electrons but potential wells for holes. For the coupled QR structure, the region sandwiched between two QRs forms a potential reservoir of quasi-bound electrons. Electrons in these states, though look like bound ones, would ultimately tunnel out of the reservoir through barriers. Multiband perfectly-matched layers are introduced to model the tunneling of quasi-bound states into open space. Resonance peaks are observed on the absorption spectra of type-II coupled QRs due to the formation of quasi-bound states in conduction bands, but no resonance exist in the uncoupled QR. The tunneling time of these metastable states can be extracted from the resonance and is in the order of ten femtoseconds. Absorption of coupled QRs is significantly enhanced as compared to that of uncoupled ones in certain spectral windows of interest. These features may improve the performance of photon detectors and photovoltaic devices based on type-II semiconductor nanostructures.
Enhanced Absorption Due to Formation of Quasi-Bound States in Type-II Coupled Quantum Rings
(2018-03-01)
Hsieh, Chi-Ti
;
Lin, Shih-Yen
;
Chang, Shu-Wei
;
光電工程學系
;
Department of Photonics
The absorption of type-II nanostructures is often weaker than type-I counterpart due to spatially indirect optical transitions. This phenomenon limits the application of type-II nanostructures in photon detections. In this paper, we show that with proper arrangements of conduction barriers, the formation of quasi-bound states can significantly boost up the absorption of type-II coupled quantum rings. Meanwhile, the rapid tunneling of electrons in these leaky states should make the corresponding external quantum efficiency comparable to that of single (uncoupled) rings. These featuresmay improve the performance of photon detectors based on type-II semiconductor nanostructures.
以混合醇胺溶液(MEA/AMP)去除二氧化碳溫室氣體之可行性研究
(1999)
白曛綾
;
HSUN-LINGBAI
;
交通大學環境工程研究所
Organic solar cells comprising multiple-device stacked structures exhibiting complementary absorption behavior
(2014-01-01)
Lin, Wei-Ting
;
Lin, Yen-Tseng
;
Chou, Chu-Hsien
;
Chen, Fang-Chung
;
Hsu, Chain-Shu
We developed organic solar cells based on multiple-device stacked structures featuring complementary absorption behavior. The first, semitransparent (ST) subcell featured an inverted structure; its anode comprised a MoO3/Ag bilayer. This structure provided a transmittance of greater than 35% in the visible region. The second subcell, featuring a low-band-gap small molecule in its photoactive layer, was stacked onto the ST device; the two subcells could be connected either in series or in parallel. Because the two subcells exhibited complementary absorption behavior, their stacked structure connected in parallel displayed a power conversion efficiency of 4.37%, greater than those of the isolated subcells. (C) 2013 Elsevier B.V. All rights reserved.
THz Optical Constants of the Liquid Crystal MDA-00-3461
(2011)
Ku, Cheng-Pin
;
Shih, Chih-Chang
;
Lin, Chia-Jen
;
Pan, Ru-Pin
;
Pan, Ci-Ling
We have measured the far infrared optical constants of MDA-00-3461 at 25 degrees C by using terahertz time-domain spectroscopy. The extraordinary and ordinary refractive indices of MDA-00-3461 are n(e) approximate to 1.74 and n(o) approximate to 1.54, or a birefringence of 0.20 from 0.3 to 1.4 THz. The extinction coefficient of MDA-00-3461 is relatively small. There are no absorption peaks in the frequency range investigated.
Photoerasable Organic Nonvolatile Memory Devices Based on Hafnium Silicate Insulators
(2011-12-01)
Chen, Fang-Chung
;
Chang, Hsiao-Fen
;
光電工程學系
;
顯示科技研究所
;
Department of Photonics
We have prepared photoerasable organic nonvolatile memories using high-dielectric (high-k) hafnium silicate as device insulators. The high-k material can effectively lower the operating voltage of the organic memory devices. The nonvolatile memory can be written by applying a gate bias and be effectively erased by photon illumination. The spectral study of the photoinduced recovery effect indicated that the erasing mechanism should be relevant to the recombination between the trapped charges and the photogenerated exctions.
Electrical and Photosensitive Characteristics of a-IGZO TFTs Related to Oxygen Vacancy
(2011-04-01)
Yao, Jianke
;
Xu, Ningsheng
;
Deng, Shaozhi
;
Chen, Jun
;
She, Juncong
The electrical and photosensitive characteristics of amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) related to the oxygen vacancies V(O) are discussed. With the filling of V(O) of ratio from 14 to 8, the electron density of the a-IGZO channel decreases from 7.5 to 3.8 (x10(16) cm(-3)); the saturation mobility of the TFT decreases from 3.1 to 1.4 cm(2)/(V . s); the threshold voltage increases from 7 to 11 V for the TFT with a lower on-current; and the subthreshold slope increases from 2.4 to 4.4 V/dec for the TFT with a higher interface defect density of 4.9 x 10(11) cm(-2), the worst electrical stability of Delta V(th) similar to 10 V, and a hysteresis-voltage decrease from 3.5 to 2 V. The photoreaction properties of a-IGZO TFTs are also sensitive to the oxygen-content-related absorption of the a-IGZO channel. With the lowest content of oxygen in the channel, the TFT has the largest photocurrent gain of 50 mu A (V(g) = 30 V; V(d) = 10 V) and decrease in V(th) (|Delta V(th)| similar to 5 V) at a high light intensity. The light-induced change of TFT characteristics is totally reversible with the time constant for recovery of about 2.5 h.

學術出版;;Publications

Browse

Filters

Settings

Sort By

Results per page

🏛️國立陽明交通大學機構典藏

Search Results