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891.
Amorphous TaOx thin films were deposited at different temperatures, and the resistance switching properties of the Pt/TaOx/Pt structure were investigated. X‐ray photoelectron spectroscopy showed that the amount of Ta2O5 in the film decreased and the content of Ta suboxides increased substantially when the growth temperature was increased. Unipolar resistance switching near the anode was stable only for TaOx film grown at room temperature. The experimental results revealed the critical effect of the film composition on the resistance switching behavior of TaOx films. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
892.
Dong Ho Kim Su Jin Kim Seung Hwan Kim Tak Jeong Sung Min Hwang Tae Geun Kim 《固体物理学:研究快报》2011,5(8):274-276
The authors report upon the increased light‐output power (Pout) via a reduction in the forward voltage (Vf) for nonpolar a ‐plane GaN LEDs using Ni/Al/Ni/Au n‐type ohmic contacts. The specific contact resistivity of the Ni/Al/Ni/Au contact is found to be as low as 5.6 × 10–5 whereas that of a typical Ti/Al/Ni/Au contact is 6.8 × 10–4 Ω cm2, after annealing at 700 °C. The X‐ray photoelectron spectroscopy results show that the upward surface band bending is less pronounced for the Ni/Al contact compared to the Ti/Al contact, leading to a decrease in the effective Schottky barrier height (SBH). The Vf of the nonpolar LEDs decreases by 10% and Pout increases by 15% when the Ni/Al/Ni/Au scheme is used instead of the typical Ti/Al/Ni/Au metal scheme. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
893.
894.
Min Hwan Lee Kyung Min Kim Seul Ji Song Sang Ho Rha Jun Yeong Seok Ji Sim Jung Gun Hwan Kim Jung Ho Yoon Cheol Seong Hwang 《Applied Physics A: Materials Science & Processing》2011,102(4):827-834
The bipolar resistive switching mechanisms of a p-type NiO film and n-type TiO2 film were examined using local probe-based measurements. Scanning probe-based current–voltage (I–V) sweeps and surface potential/current maps obtained after the application of dc bias suggested that resistive switching is
caused mainly by the surface redox reactions involving oxygen ions at the tip/oxide interface. This explanation can be applied
generally to both p-type and n-type conducting resistive switching films. The contribution of oxygen migration to resistive
switching was also observed indirectly, but only in the cases where the tip was in (quasi-) Ohmic contact with the oxide. 相似文献
895.
A combination of infrared spectroscopy, X-ray photoelectron spectroscopy and density functional theory has been used to investigate the adsorption behavior of glycine at the Ge(100) ? 2 × 1 surface under ultrahigh vacuum conditions. Comparison of experimental and simulated IR spectra indicates that at 310 K, glycine adsorbs on Ge(100) ? 2 × 1 via O–H dissociation, with some fraction of the products also forming an N dative bond to a neighboring germanium atom. O–Ge dative bonding is not observed. As coverage increases, the surface concentration of the monodentate O–H dissociated adduct increases, while that of the N dative-bonded species appears constant. XPS data support and clarify the IR findings and reveal new insights, including the presence at higher coverage of a minor product that has undergone dual O–H and N–H dissociation. These findings are supported by the calculated energy diagrams, which indicate that the reaction of a glycine molecule on the Ge(100) ? 2 × 1 surface via O–H dissociation and interdimer N dative bonding is both kinetically and thermodynamically favorable and that N–H dissociation of this adduct is feasible at room temperature given incomplete thermal accommodation along the reaction pathway. 相似文献
896.
We investigate the high-frequency timing jitter spectral density of mode-locked fiber lasers in different mode-locked regimes. Quantum-noise-limited timing jitter spectra of mode-locked-regime-switchable Yb fiber lasers are measured up to the Nyquist frequency with sub-100-as resolution. The integrated rms timing jitter of soliton, stretched-pulse, and self-similar Yb fiber lasers is measured to be 1.8, 1.1, and 2.9 fs, respectively, when integrated from 10 kHz to 40 MHz. The distinct behavior of jitter spectral density related to pulse formation mechanisms is revealed experimentally for the first time. 相似文献
897.
Jung Tae ParkJoo Hwan Koh Jin Ah SeoYong Soo Cho Jong Hak Kim 《Applied Surface Science》2011,257(20):8301-8306
We report on the novel ternary hybrid materials consisting of semiconductor (TiO2), metal (Ag) and polymer (poly(oxyethylene methacrylate) (POEM)). First, a hydrophilic polymer, i.e. POEM, was grafted from TiO2 nanoparticles via the surface-initiated atom transfer radical polymerization (ATRP) technique. These TiO2-POEM brush nanoparticles were used to template the formation of Ag nanoparticles by introduction of a AgCF3SO3 precursor and a NaBH4 aqueous solution for reduction process. Successful grafting of polymeric chains from the surface of TiO2 nanoparticles and the in situ formation of Ag nanoparticles within the polymeric chains were confirmed using transmission electron microscopy (TEM), UV-vis spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). FT-IR spectroscopy also revealed the specific interaction of Ag nanoparticles with the CO groups of POEM brushes. This study presents a simple route for the in situ synthesis of both metal and polymer confined within the semiconductor, producing ternary hybrid inorganic-organic nanomaterials. 相似文献
898.
Shih-Chang LiangDu-Cheng Tsai Zue-Chin ChangHuan-Shin Sung Yi-Chen LinYi-Jung Yeh Min-Jen Deng Fuh-Sheng Shieu 《Applied Surface Science》2011,258(1):399-403
In this study, (TiVCrZrHf)N multi-component coatings with quinary metallic elements were deposited by reactive magnetron sputtering system. The composition, structure, and mechanical properties of the coatings deposited at different N2 flow rates were investigated. The (TiVCrZrHf)N coatings deposited at N2 flow rates of 0, 1, and 2 SCCM showed an amorphous structure, whereas those deposited at N2 flow rates of 4 and 6 SCCM showed a simple face-centered cubic solid solution structure. A saturated nitride coating was obtained for N2 flow of 4 SCCM and higher. By increasing N2 flow to 4 SCCM, the hardness and modulus reached a maximum value of 23.8 ± 0.8 and 267.3 ± 4.0 GPa, respectively. 相似文献
899.
We correct some statements in the paper mentioned in the title. 相似文献
900.
The derivative of self-intersection local time (DSLT) for Brownian motion was introduced by Rosen (2005) and subsequently used by others to study the L2 and L3 moduli of continuity of Brownian local time. A version of the DSLT for fractional Brownian motion (fBm) was introduced in Yan et al. (2008); however, the definition given there presents difficulties, since it is motivated by an incorrect application of the fractional Itô formula. To rectify this, we introduce a modified DSLT for fBm and prove existence using an explicit Wiener chaos expansion. We will then argue that our modification is the natural version of the DSLT by rigorously proving the corresponding Tanaka formula. This formula corrects a formal identity given in both Rosen (2005) and Yan et al. (2008). In the course of this endeavor we prove a Fubini theorem for integrals with respect to fBm. The Fubini theorem may be of independent interest, as it generalizes (to Hida distributions) similar results previously seen in the literature. As a further byproduct of our investigation, we also provide a small correction to an important technical second-moment bound for fBm which has appeared in the literature many times. 相似文献