Browsing by Author "Chang, C. -Y."

Now showing 1 - 9 of 9

A novel streptococci-conserved beta-lactamase involved in ampicillin resistance of Streptococcus pneumoniae
(2015-07-01)
Li, Y. -K.
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Chang, C. -Y.
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Li, B. -R.
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交大名義發表
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應用化學系
Analysis of the Short-Term Response in the Drain Current of a-IGZO TFT to Light Pulses
(2017-07-01)
Liu, H. -W.
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Chan, P. -C.
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Lin, J. -H.
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Chang, C. -Y.
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Tai, Y. -H.
In this letter, the response in the drain current (I-D) of the amorphous indium-gallium-zinc oxide thin-film transistors under positive-bias illumination stress is measured with respect to time in less than 5 s under light pulseswith altering frequencies and duty ratios. The curves of I-D under the light pulses are affected by the different defect-reacting rates under illumination and in the dark. By taking the derivative of ID, the trend of the change in the number of defects becomes clear. The total behavior of I-D in response to light pulses can be fairly predicted by the integral of the derivative terms with a correction factor of charge trapping.
Defect selective passivation in GaN epitaxial growth and its application to light emitting diodes
(2009-11-23)
Lo, M. -H.
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Tu, P. -M.
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Wang, C. -H.
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Cheng, Y. -J.
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Hung, C. -W.
A defect selective passivation method to block the propagation of threading dislocations in GaN epitaxial growth is demonstrated. The defect selective passivation is done by using defect selective chemical etching to locate defect sites, followed by silicon oxide passivation of the etched pits, and epitaxial over growth. The threading dislocation density in the regrown epilayer is significantly improved from 1x10(9) to 4x10(7) cm(-2). The defect passivated epiwafer is used to grow light emitting diode and the output power of the fabricated chip is enhanced by 45% at 20 mA compared to a reference one without using defect passivation.
Electrically driven nanoarrow array green LED
(2012)
Chang, J. -R.
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Chang, S. -P.
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Chen, Y. -C.
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Sou, K. -P.
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Cheng, Y. -J.
An electrically driven nanopyramid green light emitting diode (LED) was demonstrated. The nanopyramid arrays were fabricated from a GaN substrate by patterned nanopillar etch, pillar side wall passivation, and epitaxial regrowth. Multiple quantum wells were selectively grown on the facets of the nanopyramids. The fabricated LED emits green wavelength under electrical injection. The emission exhibits a less carrier density dependent wavelength shift and higher internal quantum efficiency as compared with a reference c-plane sample at the same wavelength. It shows a promising potential for using nanopyramid in high In content LED applications.
Electrically driven nanopyramid green light emitting diode
(2012-02-06)
Chang, S. -P.
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Chen, Y. -C.
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Huang, J. -K.
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Cheng, Y. -J.
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Chang, J. -R.
An electrically driven nanopyramid green light emitting diode (LED) was demonstrated. The nanopyramid arrays were fabricated from a GaN substrate by patterned nanopillar etch, pillar side wall passivation, and epitaxial regrowth. Multiple quantum wells were selectively grown on the facets of the nanopyramids. The fabricated LED emits green wavelength under electrical injection. The emission exhibits a less carrier density dependent wavelength shift and higher internal quantum efficiency as compared with a reference c-plane sample at the same wavelength. It shows a promising potential for using nanopyramid in high In content LED applications. (C) 2012 American Institute of Physics. [doi:10.1063/1.3681363]
Fabrication and luminescent properties of core-shell InGaN/GaN multiple quantum wells on GaN nanopillars
(2012-06-25)
Chang, J. -R.
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Chang, S. -P.
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Li, Y. -J.
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Cheng, Y. -J.
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Sou, K. -P.
Core-shell InGaN/GaN multiple quantum wells (MQWs) on GaN nanopillars were fabricated by top-down etching followed by epitaxial regrowth. The regrowth formed hexagonal sidewalls and pyramids on the nanopillars. The cathodoluminescence of MQWs blue shifts as the location moves from top to bottom on both the pillar sidewalls and pyramid facets, covering a spectral linewidth of about 100 nm. The MQWs on the pillar sidewalls have a higher InN fraction than those on the pyramid facets. The photoluminescent wavelength is stable over two orders of carrier density change due to the smaller quantum confined Stark effect on the nanopillar facets. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4731629]
Optical properties of self assembled GaN polarity inversion domain boundary
(2011-07-11)
Liu, M. -C.
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Cheng, Y. -J.
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Chang, J. -R.
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Hsu, S. -C.
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Chang, C. -Y.
We report the fabrication of GaN lateral polarity inversion heterostructure with self assembled crystalline inversion domain boundaries (IDBs). The sample was fabricated by two step molecular-beam epitaxy (MBE) with microlithography patterning in between to define IDBs. Despite the use of circular pattern, hexagonal crystalline IDBs were self assembled from the circular pattern during the second MBE growth. Both cathodoluminescent (CL) and photoluminescent (PL) measurements show a significant enhanced emission at IDBs and in particular at hexagonal corners. The ability to fabricate self assembled crystalline IDBs and its enhanced emission property can be useful in optoelectronic applications. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3610449]
Oxidation of Ag Nanowires Studied by Terahertz Spectroscopy
(2013-01-01)
Tsai, Y. -J.
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Chang, C. -Y.
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Yu, P.
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Ahn, H.
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光電工程學系
The electrical conductivity of silver nanowire assembly is measured by using terahertz spectroscopy. Growth of the surface-oxidized layer on silver nanowires hinders electron transportation through the nanowire-to-nanowire junction and reduces the conductivity of nanowire network.
Voltage Transfer Characteristic Matching by Different Nanosheet Layer Numbers of Vertically Stacked Junctionless CMOS Inverter for SoP/3D-ICs applications
(2018-01-01)
Sung, P. -J.
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Chang, C. -Y.
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Chen, L. -Y.
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Kao, K. -H.
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Su, C. -J.
For the first time, CMOS inverters with different numbers of vertically stacked junctionless (JL) nanosheets (NSs) are demonstrated. All fabrication steps were below 600 degrees C, and 8-nm thick poly-Si NSs with smooth surface roughness were formed by a dry etching process. Compared to single channel devices, stacked n/p-channel FETs exhibit higher on-current with low leakage current. Furthermore, a common-gate process was performed for the fabrication of CMOS inverters. By adjusting the NS layer numbers for n/pFETs, respectively, the voltage transfer characteristics (VTCs) of the CMOS inverter can be matched much better to reduce the noise margin due to on-current matching without area penalty. This work experimentally demonstrates a new configuration of CMOS inverters on stacked NSs, which is promising for System-on-Panel (SoP) and 3D-ICs applications.