Browsing by Author "Chu, Yu Cheng"

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Degradation of AlGaInP light emitting diodes under reverse-bias operations in salty water vapor
(2015-08-01)
Chen, Hsiang
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Chu, Li-Chen
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Lee, Ming Ling
;
Kang, Nai Chung
;
Shei, Shih-Chang
GaP-based light emitting diodes (LEDs) reliability tests are crucial to further development for high-performance LED lighting technology. In this study, we perform reverse-bias stress tests for LEDs in water vapor and salty water vapor ambient, respectively. The results indicate that salty water vapor can quickly degrade LEDs. To investigate the failure mechanisms, electrical measurements, forward-bias and reverse-bias electroluminescence images, and multiple material analyses have been taken to study the failure mechanism. Results indicate that NaCl clustering solids and atom diffusion may cause deformation of the electrode and enhance the degradation of the LEDs. (c) 2014 Elsevier Ltd. All rights reserved.
Effects of N-2 and O-2 annealing on the multianalyte biosensing characteristics of CeO2-based electrolyte-insulator-semiconductor structures
(2014-04-01)
Kao, Chyuan Haur
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Chen, Hsiang
;
Lee, Ming Ling
;
Liu, Che Chun
;
Ueng, Herng-Yih
A CeO2-based multi-analyte electrolyte-insulator-semiconductor (EIS) biosensor has been fabricated on silicon substrate. To enhance the material quality and sensing performance, annealing treatment in N-2 and O-2 ambient has been incorporated. To examine the annealing effects, material analyses were conducted using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) to identify optimal treatment conditions. Furthermore, sensing performance for various ions of Na+, K+, urea, and glucose has also been tested. Results indicate that the membrane annealed at 800 degrees C in O-2 ambience exhibited a better performance with higher multianalyte sensitivity and a lower drift rate compared with the membrane annealed in N-2 ambience. Oxygen in O-2 ambience may cause stronger reflow and fill in the oxygen vacancy so that the material properties and sensing capability can be improved in O-2 annealing ambience. (C) 2014 Elsevier B.V. All rights reserved.
Multianalyte biosensor based on pH-sensitive ZnO electrolyte-insulator-semiconductor structures
(2014-05-14)
Kao, Chyuan Haur
;
Chen, Hsiang
;
Lee, Ming Ling
;
Liu, Che Chun
;
Ueng, Herng-Yih
Multianalyte electrolyte-insulator-semiconductor (EIS) sensors with a ZnO sensing membrane annealed on silicon substrate for use in pH sensing were fabricated. Material analyses were conducted using X-ray diffraction and atomic force microscopy to identify optimal treatment conditions. Sensing performance for various ions of Na+, K+, urea, and glucose was also tested. Results indicate that an EIS sensor with a ZnO membrane annealed at 600 degrees C exhibited good performance with high sensitivity and a low drift rate compared with all other reported ZnO-based pH sensors. Furthermore, based on well-established pH sensing properties, pH-ion-sensitive field-effect transistor sensors have also been developed for use in detecting urea and glucose ions. ZnO-based EIS sensors show promise for future industrial biosensing applications. (C) 2014 AIP Publishing LLC.