Browsing by Author "Peng, L. -H."

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Depolarization field mitigated domain engineering in nickel diffused lithium tentalate
(2008-03-03)
Peng, L. -H.
;
Tseng, Y. -P.
;
Lin, K. -L.
;
Huang, Z. -X.
;
Huang, C. -T.
We demonstrated a domain reversal mechanism on Z-cut congruent-grown lithium tentalate (LiTaO(3)) composed of nickel (Ni) diffusion followed by pulse field poling. Domain nucleation and forward growth were found confined to the nondiffused regions, where the commonly observed serrated domain fronts in poled LiTaO(3) were absent in this work. These observations are ascribed to the formation of domain nucleation barrier by the depolarization field and reveal the divergence effect in the ferroelectric spontaneous polarization at the domain boundary due to Ni diffusion. This mechanism simplifies the fabrication of periodically poled LiTaO(3) for second-harmonic generation in the blue spectral regime. (c) 2008 American Institute of Physics.
In-Ga-O based double-heater phase change memory cell
(2008)
Wang, S. -L.
;
Chen, C. -Y.
;
Hsieh, M. -K.
;
Lee, W. -C.
;
Kung, A. H.
We report a new type of phase-change materials based upon the compound of In-Ga-O. It is found to exhibit two-order of magnitude resistivity change between the high-resistive amorphous phase and the low-resistive cubic phase at a phase-change temperature similar to 250 degrees C. When the In-Ga-O is incorporated into a nonvolatile phase change memory (PCM) device with a double-heater (DH) structure, it exhibits an on/off resistance ratio of 1000 and cycling over 300 times which are superior to those observed on a single-heater (SH) PCM device. These results, together with a low bias point of 70 mu A at 6.5 volt and 1.5mA at 3.5 volt, respectively, for set/ reset operation of the DH-PCM device to the crystalline/amorphous state, suggest that In-Ga-O is a promising material candidate for low power application of PCM devices.
Optical interference in nonlinear photonic crystals
(2007-11-01)
Lai, Chien-Jen
;
Peng, L. -H.
;
Kung, A. H.
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光電工程學系
;
Department of Photonics
A model to analyze the interaction of the parametric fields being generated in a two-dimensional nonlinear photonic crystal has been developed. The analysis provides details of the interference of the generated wave(s) both inside and in the region just outside the crystal. The results are verified by second-harmonic generation in a LiNbO3 crystal that has been poled with a tetragonal inverted domain structure. (c) 2007 Optical Society of America.
Phase-change memory devices based on gallium-doped indium oxide
(2009-03-16)
Wang, S. -L.
;
Chen, C. -Y.
;
Hsieh, M. -K.
;
Lee, W. -C.
;
Kung, A. H.
We report repetitive phase-change memory (PCM) activity via the high- to low-resistance state transition in gallium-doped indium oxide (Ga:InO) induced by nanosecond electric pulses. The amorphous-to-crystalline phase transition of Ga:InO is found to occur at a crystallization temperature of similar to 250 degrees C with an activation energy of 1.27 +/- 0.07 eV. At the phase transition, we observe a change in two orders of magnitude in the PCM-device resistance, which can be correlated with the formation of (211) and {222} crystallites of bixbyite cubic In(2)O(3). We ascribe the phase-change mechanism to the Joule heating effect in Ga:InO.