Browsing by Author "Wang, Hsin-Ping"

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An organic hydrogel film with micron-sized pillar array for real-time and indicator-free detection of Zn(2+)
(2011-11-01)
Chao, Yu-Chiang
;
Huang, Yi-Sa
;
Wang, Hsin-Ping
;
Fu, Ssu-Ming
;
Huang, Chien-Hao
A hydrogel sensing film for a real-time and indicator-free detection of Zn(2+) is developed by embedding a fluorescent indicator 11,16-bis( phenyl)-6,6,21,21-tetramethyl-m-benzi-6,21-porphodimethene in a hydrogel host poly(2-hydroxyethyl methacrylate). The sensing film shows high stability and selectivity to Zn(2+). The sensitivity of the sensing film is increased by fabricating a micron-sized pillar array on the surface of the sensing film to increase the surface area. For Zn(2+) concentrations of 10 (4) and 10 (3) M, the response time is 30 and 3 s, respectively. (C) 2011 Elsevier B.V. All rights reserved.
An organic hydrogel film with micron-sized pillar array for real-time and indicator-free detection of Zn2+
(2011-11-01)
Chao, Yu-Chiang
;
Huang, Yi-Sa
;
Wang, Hsin-Ping
;
Fu, Ssu-Ming
;
Huang, Chien-Hao
A hydrogel sensing film for a real-time and indicator-free detection of Zn2+ is developed by embedding a fluorescent indicator 11,16-bis( phenyl)-6,6,21,21-tetramethyl-m-benzi-6,21-porphodimethene in a hydrogel host poly(2-hydroxyethyl methacrylate). The sensing film shows high stability and selectivity to Zn2+. The sensitivity of the sensing film is increased by fabricating a micron-sized pillar array on the surface of the sensing film to increase the surface area. For Zn2+ concentrations of 10 (4) and 10 (3) M, the response time is 30 and 3 s, respectively. (C) 2011 Elsevier B.V. All rights reserved.
Photostriction of CH3NH3PbBr3 Perovskite Crystals
(2017-09-20)
Wei, Tzu-Chiao
;
Wang, Hsin-Ping
;
Li, Ting-You
;
Lin, Chun-Ho
;
Hsieh, Ying-Hui
Organic-inorganic hybrid perovskite materials exhibit a variety of physical properties. Pronounced coupling between phonon, organic cations, and the inorganic framework suggest that these materials exhibit strong light-matter interactions. The photoinduced strain of CH3NH3PbBr3 is investigated using high-resolution and contactless in situ Raman spectroscopy. Under illumination, the material exhibits large blue shifts in its Raman spectra that indicate significant structural deformations (i.e., photostriction). From these shifts, the photostrictive coefficient of CH3NH3PbBr3 is calculated as 2.08 x 10(-8) m(2) W-1 at room temperature under visible light illumination. The significant photostriction of CH3NH3PbBr3 is attributed to a combination of the photovoltaic effect and translational symmetry loss of the molecular configuration via strong translation-rotation coupling. Unlike CH3NH3PbI3, it is noted that the photostriction of CH3NH3PbBr3 is extremely stable, demonstrating no signs of optical decay for at least 30 d. These results suggest the potential of CH3NH3PbBr3 for applications in next-generation optical micro-electromechanical devices.
Photostriction of strontium ruthenate
(2017-04-24)
Wei, Tzu-Chiao
;
Wang, Hsin-Ping
;
Liu, Heng-Jui
;
Tsai, Dung-Sheng
;
Ke, Jr-Jian
Transition metal oxides with a perovskite crystal structure exhibit a variety of physical properties associated with the lattice. Among these materials, strontium ruthenate (SrRuO3) displays unusually strong coupling of charge, spin and lattice degrees of freedom that can give rise to the photostriction, that is, changes in the dimensions of material due to the absorption of light. In this study, we observe a photon-induced strain as high as 1.12% in single domain SrRuO3, which we attribute to a nonequilibrium of phonons that are a result of the strong interaction between the crystalline lattice and electrons excited by light. In addition, these light-induced changes in the SrRuO3 lattice affect its electrical resistance. The observation of both photostriction and photoresistance in SrRuO3 suggests the possibility of utilizing the mechanical and optical functionalities of the material for next-generation optoelectronics, such as remote switches, light-controlled elastic micromotors, microactuators and other optomechanical systems.