Chia-Chi Chang

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We have fabricated graphene-silicon Schottky diodes by depositing mechanically exfoliated graphene on top of silicon substrates. The resulting current-voltage characteristics exhibit rectifying diode behavior with a barrier energy of 0.41 eV on n-type silicon and 0.45 eV on p-type silicon at the room temperature. The I-V characteristics measured at 100,(More)
We report a systematic study of carrier dynamics in Al(x)Ga(1-x)As-passivated GaAs nanowires. With passivation, the minority carrier diffusion length (L(diff)) increases from 30 to 180 nm, as measured by electron beam induced current (EBIC) mapping, and the photoluminescence (PL) lifetime increases from sub-60 ps to 1.3 ns. A 48-fold enhancement in the(More)
We apply immense strain to ultralong, suspended, single-walled carbon nanotubes while monitoring their Raman spectra. We can achieve strains up to 13.7 ± 0.3% without slippage, breakage, or defect formation based on the observation of reversible change in Raman spectra. This is more than twice that of previous observations. The rate of G band downshift with(More)
A V-band fully integrated complementary push-push VCO is first presented in 0.18- /spl mu/m bulk CMOS technologies. Thin-film microstrip (TFMS) lines are utilized in the circuit to reduce the conductive substrate effect. In order to lower the phase noise, complementary cross-coupled pairs are used to generate negative conductance. The measured phase noise(More)
This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Abstract—Memristive electrical behavior has recently gained attention because of technological advances in nanostructuring, which has enabled the fabrication of working devices. However, such(More)
Highly perfect, twin-free GaAs nanosheets grown on (111)B surfaces by selective area growth (SAG) are demonstrated. In contrast to GaAs nanowires grown by (SAG) in which rotational twins and stacking faults are almost universally observed, twin formation is either suppressed or eliminated within properly oriented nanosheets are grown under a range of growth(More)
We have recently demonstrated that GaAs nanosheets can be grown by metal-organic chemical vapor deposition (MOCVD). Here, we investigate these nanosheets by secondary electron scanning electron microscopy (SE-SEM) and electron beam induced current (EBIC) imaging. An abrupt boundary is observed between an initial growth region and an overgrowth region in the(More)
We study the effect of polarized laser annealing on the crystalline structure of individual crystalline-amorphous core-shell silicon nanowires (NWs) using Raman spectroscopy. The crystalline fraction of the annealed spot increases dramatically from 0 to 0.93 with increasing incident laser power. We observe Raman lineshape narrowing and frequency hardening(More)