Browsing by Author "Wang, H. H."

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Efficient energy transfer from InGaN quantum wells to Ag nanoparticles
(2013)
Shu, G. W.
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Chiu, C. H.
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Huang, L. T.
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Lin, T. N.
;
Yang, C. C.
Nonradiative energy transfer from an InGaN quantum well to Ag nanoparticles is unambiguously demonstrated by the time-resolved photoluminescence. The distance dependence of the energy transfer rate is found to be proportional to 1/d(3), in good agreement with the prediction of the dipole interaction calculated from the Joule losses in acceptors. The maximum energy-transfer efficiency of this energy transfer system can be as high as 83%.
Interrelation of transport and optical properties in gold nanoclusters
(2010-09-20)
Shu, G. W.
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Chen, T. Y.
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Shen, J. L.
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Lin, C. A. J.
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Chang, W. H.
Temperature dependence of the electrical conductivity and photoluminescence (PL) in Au nanoclusters (NCs) is investigated. The correlation of the conductivity and PL in Au NCs at different temperatures is evident: (i) for T < 50 K, both the conductivity and PL intensity decrease with temperature, which suggests thermal structural fluctuations; (ii) for 50 K < T < 90 K, conductivity and PL are explained by variable range hopping; (iii) for 90 K < T < 170 K, simple thermal activated hopping dominates in conductivity, with a rate-equation model proposed to analyze the carrier transfer in PL. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3491288]
Interrelation of transport and optical properties in gold nanoclusters
(2010-09-20)
Shu, G. W.
;
Chen, T. Y.
;
Shen, J. L.
;
Lin, C. A. J.
;
Chang, W. H.
Temperature dependence of the electrical conductivity and photoluminescence (PL) in Au nanoclusters (NCs) is investigated. The correlation of the conductivity and PL in Au NCs at different temperatures is evident: (i) for T < 50 K, both the conductivity and PL intensity decrease with temperature, which suggests thermal structural fluctuations; (ii) for 50 K < T < 90 K, conductivity and PL are explained by variable range hopping; (iii) for 90 K < T < 170 K, simple thermal activated hopping dominates in conductivity, with a rate-equation model proposed to analyze the carrier transfer in PL. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3491288]
n-ZnO/LaAlO3/p-Si heterojunction for visible-blind UV detection
(2012-03-15)
Tasi, D. S.
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Kang, C. F.
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Wang, H. H.
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Lin, C. A.
;
Ke, J. J.
A visible-blind UV photodetector (PD) using a double heterojunction of n-ZnO/LaAlO3 (LAO)/p-Si was demonstrated. Inserted LAO layers exhibit electrical insulating properties and serve as blocking layers for photoexcited electrons from p-Si to n-ZnO, leading to an enhanced rectification ratio and a visible-blind UV detectivity of the n-ZnO/LAO/p-Si PDs due to the high potential barrier between LAO and p-Si layers (similar to 2.0 eV). These results support the use of n-ZnO/LAO/p-Si PDs in the visible-blind UV PDs in a visible-light environment. (C) 2012 Optical Society of America
The Effect of Tensile Strain on Optical Anisotropy and Exciton of m-Plane ZnO
(2015-04-01)
Wang, H. H.
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Tian, J. S.
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Chen, C. Y.
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Huang, H. H.
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Yeh, Y. C.
The near band edge emission of the tensile-strained m-plane ZnO film grown on (112)LaAlO3 substrates shows abnormal low polarization degree (rho = 0.1). The temperature dependency of polarization degree clarifies the origins of different emission peaks. In tensile-strained m-plane ZnO, the [0001] polarized state is upper shifted and is overlapping with the [11 (2) over bar0] polarized state. This phenomenon causes the abnormal low polarization degree and reveals the effect of strain on the emission anisotropy of m-plane ZnO.
Waveguide based energy transfer with gold nanoclusters for detection of hydrogen peroxide
(2014)
Lin, T. N.
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Chang, Y. L.
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Shu, G. W.
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Yuan, C. T.
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Shen, J. L.
H2O2 detection that uses fluorescence resonance energy transfer from InGaN quantum wells to Au nanoclusters via optical waveguiding has been developed. Steady and time-resolved photoluminescence studies have been used to demonstrate the waveguide-based energy transfer. H2O2 detection is achieved by the quenching of the red emission from Au nanoclusters. Advantages of the sensing technique include the capability of visual detection and large area analysis.