Browsing by Author "Chen, J. Y."

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A solid-state cation exchange reaction to form multiple metal oxide heterostructure nanowires
(2016)
Chen, Y. H.
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Huang, C. W.
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Yeh, P. H.
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Chen, J. Y.
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Lin, T. Y.
Metal oxide nanostructures have been investigated extensively due to their wide range of physical properties; zinc oxide is one of the most promising materials. It exhibits fascinating functional properties and various types of morphologies. In particular, ZnO heterostructures have attracted great attention because their performance can be modified and further improved by the addition of other materials. In this study, we successfully transformed ZnO nanowires (NWs) into multiple ZnO/Al2O3 heterostructure NWs via a solid-state cation exchange reaction. The experiment was carried out in situ via an ultrahigh vacuum transmission electron microscope (UHV-TEM), which was equipped with a video recorder. Moreover, we analyzed the structure and composition of the heterostructure NWs by Cs-corrected STEM equipped with EDS. Based on these experimental results, we inferred a cation exchange reaction ion path model. Additionally, we investigated the defects that appeared after the cation reaction, which resulted from the remaining zinc ions. These multiple heterostructure ZnO/Al2O3 NWs exhibited excellent UV sensing sensitivity and efficiency.
Biomimetic nanostructured antireflection coating and its application on crystalline silicon solar cells
(2011-07-18)
Chen, J. Y.
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Chang, W. -L.
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Huang, C. K.
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Sun, K. W.
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應用化學系
In this report, we demonstrate the implementation of biomimetic nanostructured antireflection coatings with polymethyl methacrylate (PMMA) layer on the micro-textured surface of silicon crystalline solar cells. To reduce cost, the process combines colloidal lithography, cast molding method, and reversal nanoimprint lithography. The technique is simple, low cost, and does not cause damage to the thin and brittle conventional crystalline solar cells. The antireflection properties of this biomimetic nanostructure coating are considered as effective as those of a conventional single-layer SiN(x) thin film. The resultant structures alone could reduce the average reflectance of solar cell from 13.2% to 7.8% and enhance power conversion efficiency from 12.85% to 14.2%. (C)2011 Optical Society of America
Efficiency enhancement of the poly-silicon solar cell using self-assembled dielectric nanoparticles
(2011-08-01)
Huang, C. K.
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Lin, H. H.
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Chen, J. Y.
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Sun, K. W.
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Chang, W. -L.
In this study, silica nanospheres dispersed in a surfactant solution were spin-coated on commercially available silicon solar cells to form colloidal crystals on the surface. This self-assembled nanoparticle layer served as an anti-reflection (AR) layer for solar cell devices. The self-assembled layer exhibits excellent anti-reflection properties in the UV and NIR wavelength regions, and the reflectance spectra match the theoretical prediction done using the rigorous coupled-wave analysis model. We also showed that the overall conversion efficiency of polycrystalline Si solar cells coated with the silica nanospheres was increased from 11% to 12.3% when using optimized spin-coating parameters and nanoparticle concentrations. (C) 2011 Elsevier B.V. All rights reserved.
Enhancement of the light conversion efficiency of silicon solar cells by using nanoimprint anti-reflection layer
(2010-03-01)
Chen, J. Y.
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Sun, K. W.
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應用化學系
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Department of Applied Chemistry
In this report, the results of the fabrication of nanostructured Si molds by e-beam lithography and chemical wet etching are presented. A home-made pneumatic nanoimprint system was used to transfer the mold patterns to a PMMA layer on a Si template using the spin-coating replication/hot-embossing techniques. The patterned PMMA layer was peeled off from the Si template and directly transferred onto the surface of a poly-Si P-N junction solar cell device to serve as the anti-reflection (AR) layer. It provides a simple and low-cost means for large-scale Use in the production of AR layers for improving solar cell performance. A drastic reduction in reflectivity of the AR layer over a broad spectral range was demonstrated. In addition, the great improvement on the light harvest efficiency of the solar cells from 10.4% to 13.5% using the nanostructured PMMA layer as the AR layer was validated. (C) 2009 Elsevier B.V. All rights reserved.
Growth of Vertically Aligned ZnO Nanorod Arrays as Anti-reflection Layer in Silicon Solar Cell
(2010)
Chen, J. Y.
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Sun, K. W.
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應用化學系
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Department of Applied Chemistry
We have investigated solution-grown ZnO nanorod arrays as the anti-reflection(AR) layer for Si solar cells. The nanorod morphology, controlled through synthetic chemistry, has a great effect on the AR layer performance. We demonstrate that the light harvest efficiency of the solar cells can be greatly improved from 10.4% to 12.8% by using the vertical aligned ZnO nanorod arrays as the AR layer on poly-Si solar cells.
Growth of vertically aligned ZnO nanorod arrays as antireflection layer on silicon solar cells
(2010-05-01)
Chen, J. Y.
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Sun, K. W.
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應用化學系
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Department of Applied Chemistry
In this work we investigated the effects of growth time, spin-coating rates, and solution concentration on the reflection properties of the solution-grown ZnO nanorod arrays. The vertically aligned nanorod arrays were deposited on the surface of the Si solar cells as the antireflection (AR) layer. We found that the nanorod morphology, controlled through synthetic chemistry, has a great effect on the AR layer performance. We also demonstrated that the light harvest efficiency of the solar cells was greatly improved from 10.4% to 12.8% by using the vertically aligned ZnO nanorod arrays as the AR layer on poly-Si solar cells. (C) 2010 Elsevier B.V. All rights reserved.
High performance organic light-emitting devices with doped indium-tin-oxide anodes
(2005)
Chen, T. -H.
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Wu, T. J.
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Chen, J. Y.
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Liou, Y.
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顯示科技研究所
High performance organic light-emitting devices (OLEDs) with high luminance and high luminance efficiency have been fabricated by doping indium-tin-oxide (ITO) with Hf and V. The enhanced performance was attributed to the work functions (WF) of the ITO anode been modified by deposition of a thin (15 nm) Hf or V-doped ITO overlayer. The WF values were varied from 5.0 to 5.4 eV by doping different concentrations of Hf or V into the ITO overlayer. A luminance of 1000 cd/m(2) at 6.8 V was obtained in the device with the V-doped ITO overlayer, and a luminance efficiency of 14 cd/A was achieved in the device with the Hf-doped ITO overlayer. The high performance of the OLED is believed due top the reduction of the hole injection barriers resulted from the work function modification of the ITO overlayer.
Improvement in the light conversion efficiency of silicon solar cells by pure hydrogen annealing
(2015-11-01)
Xie, M. H.
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Chen, J. Y.
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Sun, K. W.
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應用化學系
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電子工程學系及電子研究所
In this report, the effects of pure hydrogen gas annealing on series resistance (R-s), shunt resistance (R-sh), open circuit voltage (V-oc), short circuit current I-sc, fill factor, and efficiency were investigated systematically using standard, commercially available polysilicon solar cells. Improvements on the electrical characteristics, fill factors, and efficiency of the solar cells were observed after annealing by pure hydrogen gas at 350 degrees C for 15 min. In the best case, the conversion efficiency was raised by nearly 1% point. Judging from our experimental evidences, the improvement on cell performance could be mostly attributed to the reduction of R-s and improvement in Ag grid/emitter contact resistance in the cells during the annealing process. (C) 2015 Elsevier Ltd. All rights reserved.
Magnetotransport of thick Disordered CuGe Samples
(2003-02-01)
Hsu, Shih-ying
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Chen, J. Y.
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Liao, C. T.
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電子物理學系
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Department of Electrophysics
Nanostructured thin films for anti-reflection applications
(2011-05-31)
Chen, J. Y.
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Sun, K. W.
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應用化學系
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Department of Applied Chemistry
Anti-reflection (AR) thin films composed of ordered arrays of tapered nanostructures on the surface of PMMA and silicon, through the hot-embossing nanoimprint of polymer using molds prepared from e-beam lithography and hydrothermally grown ZnO nanorod arrays. The use of PMMA and ZnO nanorod thin films allows the formation of anti-reflection structures on a curved or flat surface to effectively suppress the reflectance of the incident light. It provides a simple and low-cost means for large-scale use in the production of AR layers for improving optical and optoelectronic device performance, such as solar cells and photodetectors. A drastic reduction in the reflectivity of the AR layer over a broad spectral range was demonstrated. In addition, the great improvement on the light harvest efficiency of the solar cells by over 30% using the nanostructured AR layer was validated. (C) 2011 Elsevier B.V. All rights reserved.
Standard 0.18um 1P6M CMOS IC foundry flow for accelerometer, analog readout circuit and wafer level capping package integration
(2011)
Huang, C. J.
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Chen, C. S.
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Wen, K. A.
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Cheng, Y. T.
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Chen, J. Y.
The first standard CMOS IC foundry flow is presented for the monolithic integration of MEMS sensor, analog readout circuit and wafer level capping on standard 0.18um 1P6M technology. The sensor and circuit parts are fabricated at first on the same 8 '' substrate using a standard 0.18um 1P6M CMOS process. The sensor part is then micromachined and released by a foundry-based post-CMOS DRIE process followed by wafer level capping. The test vehicle for the proposed integration flow contains a single-axial accelerometer, analog readout circuit with input common-mode feedback and QFN64 package. The measurement results show that the whole system can have 206mV/g of sensitivity and output noise is less than 250 mu g/root Hz. The proposed methodology has led a promising way for integrating MEMS, IC and package in a conventional IC foundry manufacturing flow.
Utilizing New Erbium-Doped Fiber Laser Scheme for Long-Distance Fiber Bragg Grating (FBG) Sensor System
(2015)
Yeh, C. H.
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Chen, H. Z.
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Chen, J. Y.
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Chow, C. W.
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光電工程學系
We propose and demonstrate a new erbium-doped fiber (EDF) ring laser structure for 10 km long fiber sensor application. Here, we utilize ten fiber Bragg gratings (FBGs) as fiber sensors for sensing strain change. In the experiment, we can tune the passband of tunable bandpass filter (TBF) inside a fiber ring cavity to match the Bragg wavelength of each FBG to lase corresponding wavelength. Hence, the temperature-induced shift in Bragg wavelength could be monitored. In addition, 10 km long distance single-mode fiber (SMF) can be achieved by using the proposed EDF ring laser scheme for FGB-based remote sensor system.
Utilizing simple FBG-based erbium-doped fiber architecture for remote temperature sensing
(2015-10-01)
Yeh, C. H.
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Chow, C. W.
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Chen, J. Y.
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Chen, H. Z.
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Chen, J. H.
In this work, we demonstrate experimentally an erbium-doped fiber (EDF) ring laser structure for remote temperature sensing by using fiber Bragg gratings (FBGs) in C-band. Based on the proposed EDF laser configuration, the remote temperature sensing distance is achieved at 50 km. Here, ten FBGs are employed at the remote side for temperature sensing. By tuning the optical tunable filter (TF), the corresponding Bragg wavelength from each FBG can be monitored in the proposed EDF laser. As a result, in the temperature range from 20 to 82 degrees C, the maximum drift of Bragg wavelength can be detected at 0.84 nm.