Browsing by Author "Hsueh, H. T."

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Anisotropy light extraction with high polarization ratio from photonic crystal fight-emitting diodes
(2008)
Lai, Chun-Feng
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Kuo, Hao-Chung
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Lu, Tien-Chang
;
Wang, Shing-Chang
;
Chao, C. H.
The azimuthal anisotropy of GaN photonic crystal light-emitting diode is investigated using an annular structure. The extracted light distribution has P/S ratio of 5.5 for fight propagating in Gamma X direction and 2.1 for Gamma M direction. @2007 Optical Society of America
Anisotropy of light extraction from two-dimensional photonic crystal light-emitting diodes
(2007-09-17)
Lai, Chun-Feng
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Kuo, H. C.
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Chao, C. H.
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Hsueh, H. T.
;
Wang, J.-F. T.
Anisotropic light extraction of photonic crystal (PhC) light-emitting diodes in the azimuthal direction has been investigated with an annular structure of triangular PhC lattice. The optical images of the photoluminescence light extraction are obtained with laser excitation. For increasing lattice constant, sixfold symmetric patterns with varying numbers of petals in multiples of six are observed and analyzed. A map of the anisotropy for various lattice constants and numerical apertures is constructed. Several features of light propagations associated with the PhC are observed including the focusing and collimating behaviors.(c) 2007 American Institute of Physics.
Azimuthal anisotropy of light extraction from photonic crystal light-emitting diodes
(2008)
Lai, Chun-Feng
;
Kuo, H. C.
;
Chao, C. H.
;
Hsueh, H. T.
;
Wang, J. -F. T.
Photonic crystal (PhC) light-emitting diodes (LEDs) exhibiting anisotropic light extraction have been investigated experimentally and theoretically. It is found that the anisotropic light extraction strongly depends on the lattice constant and orientation. Optical images of the anisotropy in the azimuthal direction are obtained using annular structure with triangular lattice. 6-fold symmetric light extraction patterns with varying number of petals are observed. More petals in multiple of 6 appear in the observed image with lattice constant increasing. This anisotropic behavior suggests a new means to optimize the PhC design of GaN LED for light extraction.
Nanomanipulation measurement and PIC simulation of field-emission properties from a single crystallized silicon nano-emitter
(2007-06-06)
Cheng, T. C.
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Hsu, K. H.
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Chen, P. Y.
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Huang, W. J.
;
Wu, J. S.
The field-emission characteristics of a single silicon nano-emitter were investigated by means of experiments and simulation models. The emitter array was fabricated by dry etching using an inductively coupled plasma (ICP) through a three-step process. A novel experimental technique was developed to precisely measure the field-emission current from a single silicon emitter. Accompanying these measurements, a parallelized three-dimensional particle-in-cell (PIC) code, in which the Fowler - Nordheim emission law was implemented at the emitter surface, was employed to simulate the emission current both with and without taking into account the space charge effect. Results show that the simulated I - V relationship when considering the space - charge effect was in excellent agreement with the actual measurements. Noticeably, the predicted turn-on voltage was found to be within only 9.3% of the experimental data. In addition, both the predicted and experimental data demonstrated a consistent single linear slope in the FN plot, which indicates that the field emission from a single silicon tip is a barrier-tunnelling, quantum mechanical process.