The Experts below are selected from a list of 64218 Experts worldwide ranked by ideXlab platform
Wei Huang - One of the best experts on this subject based on the ideXlab platform.
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The effect of porous structure of PMMA tunneling Dielectric Layer on the performance of nonvolatile floating-gate organic field-effect transistor memory devices
Organic Electronics, 2016Co-Authors: Mingdong Yi, Haifeng Ling, Yizheng Wang, Chunyuan Song, Wen Li, Wei HuangAbstract:Abstract In this paper, we used the low and high density porous structure of polymethylmethacrylate (PMMA) film as tunneling Dielectric Layer in the floating-gate organic field-effect transistor (OFET) memory devices. Compared to the thin/thick nonporous structure of PMMA tunneling Layer, the porous structure of PMMA tunneling Layer had positive impacts on the device performance of the floating-gate OFET memory devices. Moreover, it was found that the memory performance was also increased as pore density of PMMA film increased. The atomic force microscopy (AFM) results of both porous structure of PMMA film and pentacene film on porous structure of PMMA film revealed that high density porous structure of PMMA tunneling Layer can produce larger tunneling area and more electron transfer paths between pentacene film and PMMA film, which resulted in high electron capture and release efficiency of the floating-gate OFET memory devices with porous structure of PMMA tunneling Layer. In addition, our porous structure of PMMA tunneling Layer as well as nonporous PMMA film has high electrical insulating property due to their semi-hollow structure film, which is favourable to maintain stable retention property. Eventually, the floating-gate OFET memory devices with high density porous structure of PMMA tunneling Layer showed good nonvolatile memory properties with a large memory window of about 43 V, a high ON/OFF current ratio of about 104, and stable endurance and retention properties. Our results provided a new strategy to achieve the high performance floating-gate OFET memory devices.
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the mechanical bending effect and mechanism of high performance and low voltage flexible organic thin film transistors with a cross linked pvp Dielectric Layer
Journal of Materials Chemistry C, 2014Co-Authors: Wei Huang, Yuxiu Guo, Jialin Guo, Tao Yang, Yuhua Chai, Quli Fan, Linghai XieAbstract:Low operational voltage flexible organic thin-film transistors (OTFTs) have been achieved using two Layers of cross-linked PVP as the Dielectric Layer on a flexible polyimide (PI) substrate. At low operating voltages of −4 V, the flexible OTFTs showed good performances with high field-effect mobility (∼0.56 cm2 V−1 s−1), low threshold voltage (∼−0.82 V), high on/off current ratio (∼105) and excellent electrical stability (∼2 months). During a severe mechanical bending test (104 bending cycles and a bending radius of 0.75 mm) under ambient conditions, the flexible OTFTs still showed excellent electrical performance at the low operational voltage. Moreover, the effects of the mechanical bending on the electrical parameters of the flexible OTFTs were also systematically investigated. We found that the variations of the electrical parameters of the flexible OTFTs during the mechanical bending process were closely related to the distance effect of the spacing between stretched pentacene molecules and the doping effect of H2O and O2 which were induced by the mechanical bending strains. In comparison with previously reported flexible OTFTs, the research results showed that the distance effect and doping effect were mutually independent as well as mutually related during the mechanical bending process of the flexible OTFTs.
N N Rosanov - One of the best experts on this subject based on the ideXlab platform.
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generation of unipolar half cycle pulses via unusual reflection of a single cycle pulse from an optically thin metallic or Dielectric Layer
Optics Letters, 2017Co-Authors: M V Arkhipov, R M Arkhipov, A V Pakhomov, I Babushkin, Ayhan Demircan, Uwe Morgner, N N RosanovAbstract:We propose a strikingly simple method to form approximately unipolar half-cycle optical pulses via reflection of a single-cycle optical pulse from a thin flat metallic or Dielectric Layer. Unipolar pulses in reflection arise due to specifics of one-dimensional pulse propagation. Namely, we show that the field emitted by the Layer is proportional to the velocity of the oscillating charges in the medium, instead of their acceleration. Besides, the oscillation velocity of the charges can be forced to keep a constant sign throughout the pulse duration. That is, reflection of ultrashort pulses from broad-area Layers with nanometer-scale thickness can be very different from the common reflection in the case of longer pulses and thicker Layers. This suggests a possibility of unusual transformations of few-cycle light pulses in completely linear optical systems.
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generation of unipolar half cycle pulse via unusual reflection of a single cycle pulse from an optically thin metallic or Dielectric Layer
arXiv: Optics, 2017Co-Authors: M V Arkhipov, R M Arkhipov, A V Pakhomov, I Babushkin, Ayhan Demircan, Uwe Morgner, N N RosanovAbstract:We present a significantly different reflection process from an optically thin flat metallic or Dielectric Layer and propose a strikingly simple method to form approximately unipolar half-cycle optical pulses via reflection of a single-cycle optical pulse. Unipolar pulses in reflection arise due to specifics of effectively one-dimensional pulse propagation. Namely, we show that in considered system the field emitted by a flat medium Layer is proportional to the velocity of oscillating medium charges instead of their acceleration as it is usually the case. When the single-cycle pulse interacts with linear optical medium, the oscillation velocity of medium charges can be then forced to keep constant sign throughout the pulse duration. Our results essentially differ from the direct mirror reflection and suggest a possibility of unusual transformations of the few-cycle light pulses in linear optical systems.
Zhanchen Cui - One of the best experts on this subject based on the ideXlab platform.
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a novel functional polyurethane as a Dielectric Layer for organic thin film transistors
New Journal of Chemistry, 2018Co-Authors: Xuesong Wang, Wei Wang, He Wang, Zuosen Shi, Donghang Yan, Jian Cheng, Zhanchen CuiAbstract:In this study, we design and synthesize a novel photosensitive polyurethane material as a functional Dielectric Layer, which can adjust the crystallization of para-hexaphenyl (p-6P). The novel polymer is synthesized with a new monomer 2,2-bis(hydroxymethyl)butyl 4-cyanobenzoate (HM-4-CB), which contains benzene to provide crystal nucleus sites. The grain size and density of the p-6P crystal can be controlled by the content of HM-4-CB in the polymer structure. Therefore, this method can be used to regulate the grain size of semiconductor crystals and then to change the carrier mobility of the device. The results illustrate that with a suitable grain size of the p-6P semiconductor, excellent performance in terms of charge carrier mobility can be obtained.
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organic thin film transistors with novel photosensitive polyurethane as Dielectric Layer
RSC Advances, 2016Co-Authors: He Wang, Xuehui Zhang, Qiong Zhang, Xuesong Wang, Danfeng Cao, Zuosen Shi, Donghang Yan, Zhanchen CuiAbstract:In this paper, we report the design, synthesis, and Dielectric properties of a novel photosensitive polyurethane Dielectric film used in organic thin-film transistors (OTFTs). The novel photosensitive polyurethane Dielectric film is readily fabricated by spin coating followed by curing under UV light. The film exhibits excellent insulating properties, smooth surface, and excellent photosensitive properties. The bottom-gate top-contact para-sexiphenyl (p-6P)/vanadyl-phthalocyanine (VOPc) OTFTs with photosensitive polyurethane films as the Dielectric Layer exhibit excellent performance with a mobility of 0.13 cm2 V−1 s−1, on/off ratio of 104 and ultralow leakage.
Jiyoul Lee - One of the best experts on this subject based on the ideXlab platform.
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shellac films as a natural Dielectric Layer for enhanced electron transport in polymer field effect transistors
ACS Applied Materials & Interfaces, 2018Co-Authors: Seung Woon Baek, Minho Yoon, Dohoon Hwang, Jiyoul LeeAbstract:Shellac, a natural polymer resin obtained from the secretions of lac bugs, was evaluated as a Dielectric Layer in organic field-effect transistors (OFETs) on the basis of donor (D)-acceptor (A)-type conjugated semiconducting copolymers. The measured Dielectric constant and breakdown field of the shellac Layer were ∼3.4 and 3.0 MV/cm, respectively, comparable with those of a poly(4-vinylphenol) (PVP) film, a commonly used Dielectric material. Bottom-gate/top-contact OFETs were fabricated with shellac or PVP as the Dielectric Layer and one of three different D-A-type semiconducting copolymers as the active Layer: poly(cyclopentadithiophene- alt-benzothiadiazole) with p-type characteristics, poly(naphthalene-bis(dicarboximide)- alt-bithiophene) [P(NDI2OD-T2)] with n-type characteristics, and poly(dithienyl-diketopyrrolopyrrole- alt-thienothiophene) [P(DPP2T-TT)] with ambipolar characteristics. The electrical characteristics of the fabricated OFETs were then measured. For all active Layers, OFETs with a shellac film as the Dielectric Layer exhibited a better mobility than those with PVP. For example, the mobility of the OFET with a shellac Dielectric and n-type P(NDI2OD-T2) active Layer was approximately 2 orders of magnitude greater than that of the corresponding OFET with a PVP insulating Layer. When P(DPP2T-TT) served as the active Layer, the OFET with shellac as the Dielectric exhibited ambipolar characteristics, whereas the corresponding OFET with the PVP Dielectric operated only in hole-accumulation mode. The total density of states was analyzed using technology computer-aided design simulations. The results revealed that compared with the OFETs with PVP as the Dielectric, the OFETs with shellac as the Dielectric had a lower trap-site density at the polymer semiconductor/Dielectric interface and much fewer acceptor-like trap sites acting as electron traps. These results demonstrate that shellac is a suitable Dielectric material for D-A-type semiconducting copolymer-based OFETs, and the use of shellac as a Dielectric Layer facilitates electron transport at the interface with D-A-type copolymer channels.
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Shellac Films as a Natural Dielectric Layer for Enhanced Electron Transport in Polymer Field-Effect Transistors
2018Co-Authors: Seung Woon Baek, Minho Yoon, Dohoon Hwang, Jiyoul LeeAbstract:Shellac, a natural polymer resin obtained from the secretions of lac bugs, was evaluated as a Dielectric Layer in organic field-effect transistors (OFETs) on the basis of donor (D)–acceptor (A)-type conjugated semiconducting copolymers. The measured Dielectric constant and breakdown field of the shellac Layer were ∼3.4 and 3.0 MV/cm, respectively, comparable with those of a poly(4-vinylphenol) (PVP) film, a commonly used Dielectric material. Bottom-gate/top-contact OFETs were fabricated with shellac or PVP as the Dielectric Layer and one of three different D–A-type semiconducting copolymers as the active Layer: poly(cyclopentadithiophene-alt-benzothiadiazole) with p-type characteristics, poly(naphthalene-bis(dicarboximide)-alt-bithiophene) [P(NDI2OD-T2)] with n-type characteristics, and poly(dithienyl-diketopyrrolopyrrole-alt-thienothiophene) [P(DPP2T-TT)] with ambipolar characteristics. The electrical characteristics of the fabricated OFETs were then measured. For all active Layers, OFETs with a shellac film as the Dielectric Layer exhibited a better mobility than those with PVP. For example, the mobility of the OFET with a shellac Dielectric and n-type P(NDI2OD-T2) active Layer was approximately 2 orders of magnitude greater than that of the corresponding OFET with a PVP insulating Layer. When P(DPP2T-TT) served as the active Layer, the OFET with shellac as the Dielectric exhibited ambipolar characteristics, whereas the corresponding OFET with the PVP Dielectric operated only in hole-accumulation mode. The total density of states was analyzed using technology computer-aided design simulations. The results revealed that compared with the OFETs with PVP as the Dielectric, the OFETs with shellac as the Dielectric had a lower trap-site density at the polymer semiconductor/Dielectric interface and much fewer acceptor-like trap sites acting as electron traps. These results demonstrate that shellac is a suitable Dielectric material for D–A-type semiconducting copolymer-based OFETs, and the use of shellac as a Dielectric Layer facilitates electron transport at the interface with D–A-type copolymer channels
Yuxiu Guo - One of the best experts on this subject based on the ideXlab platform.
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the mechanical bending effect and mechanism of high performance and low voltage flexible organic thin film transistors with a cross linked pvp Dielectric Layer
Journal of Materials Chemistry C, 2014Co-Authors: Wei Huang, Yuxiu Guo, Jialin Guo, Tao Yang, Yuhua Chai, Quli Fan, Linghai XieAbstract:Low operational voltage flexible organic thin-film transistors (OTFTs) have been achieved using two Layers of cross-linked PVP as the Dielectric Layer on a flexible polyimide (PI) substrate. At low operating voltages of −4 V, the flexible OTFTs showed good performances with high field-effect mobility (∼0.56 cm2 V−1 s−1), low threshold voltage (∼−0.82 V), high on/off current ratio (∼105) and excellent electrical stability (∼2 months). During a severe mechanical bending test (104 bending cycles and a bending radius of 0.75 mm) under ambient conditions, the flexible OTFTs still showed excellent electrical performance at the low operational voltage. Moreover, the effects of the mechanical bending on the electrical parameters of the flexible OTFTs were also systematically investigated. We found that the variations of the electrical parameters of the flexible OTFTs during the mechanical bending process were closely related to the distance effect of the spacing between stretched pentacene molecules and the doping effect of H2O and O2 which were induced by the mechanical bending strains. In comparison with previously reported flexible OTFTs, the research results showed that the distance effect and doping effect were mutually independent as well as mutually related during the mechanical bending process of the flexible OTFTs.