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941.
We investigated the air stabilities of threshold voltages (Vth) on gate bias stress in pentacene thin-film transistors (TFTs) with a hydroxyl-free and amorphous fluoropolymer as gate insulators. The 40-nm-thick thin films of spin-coated fluoropolymer had excellent electrical insulating properties, and the pentacene TFTs exhibited negligible current hysteresis, low leakage current, a field-effect mobility of 0.45 cm2/Vs and an on/off current ratio of 3 × 107 when it was operated at −20 V in ambient air. After a gate bias stress of 104 s, a small Vth shift below 1.1 V was obtained despite non-passivation of the pentacene layer. We have discussed that the excellent air stability of Vth was attributed to the insulator surface without hydroxyl groups. 相似文献
942.
Ming-Yung Ko Chung-Ching Shen Shuvra S. Bhattacharyya 《Journal of Signal Processing Systems》2008,50(2):163-177
Digital signal processing (DSP) applications involve processing long streams of input data. It is important to take into account
this form of processing when implementing embedded software for DSP systems. Task-level vectorization, or block processing,
is a useful dataflow graph transformation that can significantly improve execution performance by allowing subsequences of
data items to be processed through individual task invocations. In this way, several benefits can be obtained, including reduced
context switch overhead, increased memory locality, improved utilization of processor pipelines, and use of more efficient
DSP oriented addressing modes. On the other hand, block processing generally results in increased memory requirements since
it effectively increases the sizes of the input and output values associated with processing tasks. In this paper, we investigate
the memory-performance trade-off associated with block processing. We develop novel block processing algorithms that carefully
take into account memory constraints to achieve efficient block processing configurations within given memory space limitations.
Our experimental results indicate that these methods derive optimal memory-constrained block processing solutions most of
the time. We demonstrate the advantages of our block processing techniques on practical kernel functions and applications
in the DSP domain.
相似文献
Shuvra S. BhattacharyyaEmail: |
943.
M.E. Aydin 《Microelectronic Engineering》2008,85(8):1836-1841
The electrical and interface state density properties of the Ni/4H-nSiC/PCBM/Au diode have been investigated by current-voltage, capacitance-voltage and conductance-frequency methods. The ideality factor, barrier height and series resistance values of the diode were found to be 2.28, 1.10 eV and 3.76 × 104 Ω, respectively. The diode shows a non-ideal I-V behaviour with an ideality factor greater than unity that could be ascribed to the interfacial layer, interface states and series resistance. The obtained barrier height (1.10 eV) of the Ni/4H-nSiC/PCBM/Au diode is lower than that of Ni/4H-nSiC diode (1.32 eV). This indicates that the PCBM organic layer induces a change of 160 meV in the barrier height of the Ni/4H-nSiC diode. The interface state density of the diode was determined from Gp/ω-f plots and was of order of 5.61 × 1012 eV−1 cm−2. 相似文献
944.
《Tetrahedron》2019,75(25):3504-3509
Stimuli responsive luminescent materials have attracted increasing attention for their potential application in many fields. In this work, dimethylamine substituted bisbenzocoumarins amides (DBCE and DBCP) are synthesized and their optical properties are investigated. These molecules show solvatochromic properties. The orange fluorescence emission of DBCE in crystalline state is blue-shifted to yellow emission upon grinding. The orange color could be recovered by recrystallization process. Powder wide-angle X-ray diffraction and DSC experiments reveal that the transformation from crystalline states to amorphous states under external stimuli is responsible for the mechanochromic properties. This work developed a new kind of binaphthane-type luminescent materials with blue-shifted mechanochromic properties. 相似文献
945.
Recently, molecule-based luminescent materials have been drawing extensive attention due to their desirable properties and promising applications in the fields of sensors, lighting display, and cell imaging. Crystalline polymorph is an intriguing phenomenon that the presence of multiple packing and aggregate architectures of the same molecular system. The studies on polymorphs for molecule-based fluorophores provide the opportunities to adjust the mode of molecular packing and photophysical properties, which will help to illustrate the structure-property relationship. In this review, we focus on the recent progress in various feasible methods of molecule-based crystalline polymorphism growth and their adjustable photofunctional properties, which will open up possibilities of variant optical applications. Firstly, several effective ways to prepare and screen polymorphs are sorted out. And then, we discuss the discrepant properties and multifunctional applications (such as sensors, laser, and OFET, etc.). Finally, the development trends and future prospects of these polymorphs are also briefly introduced. 相似文献
946.
947.
Samuel R. Peurifoy Thomas J. Sisto Fay Ng Michael L. Steigerwald Rongsheng Chen Colin Nuckolls 《Chemical record (New York, N.Y.)》2019,19(6):1050-1061
This Account details key developments in dimensional control of contorted aromatics for organic electronics. Coronene, perylene, pyrene, and [4]helicene, which are fragments of graphene, can be contorted using facile synthetic chemistry into large nanoribbons and nano‐architectures. In comparing contorted or higher‐dimensional graphene architectures to planar or lower‐dimensional species, the materials properties are reliably enhanced for the contorted aromatics. Examples of enhanced properties include optical absorptivity, conductivity, device photoconversion efficiency, and solubility. These enhancements are exemplified in organic photovoltaics, photodetectors, field effect transistors, and perovskite solar cells. Described herein are key advances in dimensional control of contorted aromatics that have resulted in world record photoconversion efficiencies, photodetection capabilities matching inorganic state‐of‐the‐art devices, and ~5 nm long ultrathin soluble graphene nanoribbons. 相似文献
948.
Y. Kawakami S. Iwai N. Yoneyama N. Kobayashi 《Journal of Physics and Chemistry of Solids》2008,69(12):3085-3088
Ultrafast dynamics of the photoinduced insulator (I) to metal (M) transition were investigated using femtosecond mid-infrared pump-probe spectroscopy in two-dimensional organic Mott insulators [bis (ethylenedithio)]-tetrathiafulvalene (BEDT-TTF) salts κ-(BEDT-TTF)2X (κ-(ET)2X, where X denotes anion). In κ-(d-ET)2Cu[N(CN)2]Br, a metallic state was photogenerated using a phonon-mediated mechanism: the effective bandwidth increases through the photoinduced molecular rearrangement. The mechanism differs fundamentally from the previously reported photoinduced filling control in one-dimensional Mott insulators. 相似文献
949.
V.A. Chernenko A. Fujita S. Besseghini J.I. Prez-Landazabal 《Journal of magnetism and magnetic materials》2008,320(14):e156-e159
Results of the low-temperature specific heat measurements (2–80 K) for one austenitic and three martensitic Ni–Mn–Ga ferromagnetic alloys are presented. The alloy compositions are chosen to comprise a wide span of valence electron concentrations e/a=7.3–7.78. Debye temperature (261–345 K) is found to be an increasing function of e/a while the experimental values of the Sommerfeld coefficient (2.9–3.4 mJ/mol K2) appear to be increasing in the martensitic region only. Observation of those trends rekindles the discussion about the role of vibrational and electronic contributions to the lattice instability and transformation mechanism of studied alloys. 相似文献
950.
Summary The cation-exchange behaviour of Mn(II), Cd(II), Co(II), Ni(II), Zn(II), Cu(II), Fe(III), Sc(III), Y(III), Eu(III), Dy(III), Ho(III), Yb(III), Ti(IV) and Nb(V) in malate media at various concentrations and pH, was studied with Dowex 50 WX8 resin (200–400 mesh) in the ammonium form. Separation of Fe(III)/Cu(II), Fe(III)/Cu(II)/Zn(II), Fe(III)/Co(II)/Mn(II), Cu(II)/Ni(II)/Mn(II), Fe(III)/Cu(II)/Co(II)/Mn(II), Fe(III)/Cu(II)/Ni(II)/Cd(II), Yb(III)/Eu(III), Sc(III)/Y(III),Sc(III)/Yb(III)/Dy(III) and Nb(V)/Yb(III)/Ho(III) has been achieved, among others.This work was supported by C.N.R. of Italy. 相似文献