The Experts below are selected from a list of 49275 Experts worldwide ranked by ideXlab platform
Hideo Hosono - One of the best experts on this subject based on the ideXlab platform.
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Transparent amorphous oxide Semiconductors: Materials design, electronic structure, and device applications
2017 75th Annual Device Research Conference (DRC), 2017Co-Authors: Hideo HosonoAbstract:In 1995, I presented a Materials design concept for transparent amorphous oxide Semiconductors with a large electron mobility (TAOS) at the 16'h International conference on amorphous Semiconductors along with concrete example Materials of TAOS and the paper was published in 1996 [1[. The basic concept of TAOS is that large electron mobility should be retained even in amorphous Materials if the conduction band minimum is mainly composed of spatially large spread of metal ns-orbitals.1 The validity of this design concept was demonstrated by analysis of electronic structure using photoemission experiments combined with calculations based on X-ray structural analysis[2].
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recent progress in transparent oxide Semiconductors Materials and device application
Thin Solid Films, 2007Co-Authors: Hideo HosonoAbstract:Abstract This paper reviews our recent research progress on new transparent conductive oxide (TCO) Materials and electronic and optoelectronic devices based on these Materials. First, described are the Materials including p-type Materials, deep-UV transparent TCO(β-Ga 2 O 3 ), epitaxially grown ITO with atomically flat surface, transparent electrochromic oxide (NbO 2 F), amorphous TCOs, and nanoporous semiconductor 12CaO · 7Al 2 O 3 . Second, presented are TCO-based electronic/optoelectronic devices realized to date, UV/blue LED and UV-sensors based on transparent pn junction and high performance transparent TFT using n-type TCO as an n-channel. Finally, unique optoelectronic properties (p-type degenerate conduction, transfer doping of carriers, RT-stable exciton, and large optical nonlinearity) originating from 2D-electronic nature in p-type layered oxychalcogenides are summarized along with the fabrication method of epitaxial thin films of these Materials.
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wide gap layered oxychalcogenide Semiconductors Materials electronic structures and optoelectronic properties
Thin Solid Films, 2006Co-Authors: Hidenori Hiramatsu, Kazushige Ueda, Masahiro Hirano, Toshio Kamiya, Hideo HosonoAbstract:Applying the concept of Materials design for transparent conductive oxides to layered oxychalcogenides, several p-type and n-type layered oxychalcogenides were proposed as wide-gap Semiconductors and their basic optical and electrical properties were examined. The layered oxychalcogenides are composed of ionic oxide layers and covalent chalcogenide layers, which bring wide-gap and conductive properties to these Materials, respectively. The electronic structures of the Materials were examined by normal/inverse photoemission spectroscopy and energy band calculations. The results of the examinations suggested that these Materials possess unique features more than simple wide-gap Semiconductors. Namely, the layered oxychalcogenides are considered to be extremely thin quantum wells composed of the oxide and chalcogenide layers or 2D chalcogenide crystals/molecules embedded in an oxide matrix. Observation of step-like absorption edges, large band gap energy and large exciton binding energy demonstrated these features originating from 2D density of states and quantum size effects in these layered Materials.
R Khenata - One of the best experts on this subject based on the ideXlab platform.
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first principles investigations of mn doped zinc blende zno based magnetic Semiconductors Materials for spintronic applications
Materials Science in Semiconductor Processing, 2015Co-Authors: Bakhtiar Ul Haq, Rashid Ahmed, A Shaari, A Afaq, Bashir Ahmed Tahir, R KhenataAbstract:Abstract ZnO based magnetic Semiconductors are intensively investigated because of showing strong potential as base Materials for spintronic devices. In this study, full potential linearized augmented plane-wave plus local orbitals FP-L(APW+lo) scheme of computation is used to explore the structural, electronic and magnetic properties of Manganese-doped ZnO based magnetic Semiconductors in zinc-blende (ZB) phase. For comprehensive understanding of Mn-doping effect on ZnO, several compositions of Mn:ZnO for 12.5%, 25%, 37.5%, 50%, 62.5%, 75% and 87.5% of Mn concentration are investigated. Our obtained results show a successful induction of the magnetic moment (MM) by Mn-doping into the ZnO matrix, without any geometrical deformation. However a marginal increase in the value of lattice constants is found up to 25% concentration of Mn for this system and for above compositions, it tends to decrease revealing the formation of secondary phases. It is also found that Mn:ZnO system favors ferromagnetic coupling for 12.5% and 25% of Mn contents that has been switched to anti-ferromagnetic coupling for higher Mn contents. The spin polarized electronic structure of Mn:ZnO system was calculated within the generalized gradient approximation (GGA). In addition, the Hubbard parameter was also employed to improve the electronic band structure calculations. The calculations performed at GGA+U level related to electronic band structures show zero energy gap for majority spin carriers, whereas a considerable energy gap is noted for minority spin carriers. This distinguished response of Mn:ZnO system to majority and minority spin carriers, in terms of resistivity and conductivity, highlights its importance for diverse applications as based material in spintronic devices like spin dependent transports, currents and other spin based electronic applications.
Jianzhuang Jiang - One of the best experts on this subject based on the ideXlab platform.
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h aggregation mode in triple decker phthalocyaninato europium Semiconductors Materials design for high performance air stable ambipolar organic thin film transistors
Organic Electronics, 2013Co-Authors: Hailong Wang, Jinglan Kan, Yanli Chen, Jianzhuang JiangAbstract:Abstract Two new tris(phthalocyaninato) europium complexes Eu2(Pc)[Pc(OPh)8]2 (1) and Eu2[Pc(OPh)8]3 (2) [Pc = unsubstituted phthalocyaninate; Pc(OPh)8 = 2,3,9,10,16,17,23,24-octaphenoxyphthalocyaninate], were designed and synthesized. Introduction of different number of electron-withdrawing phenoxy substituents at the phthalocyanine periphery within the triple-decker complexes not only ensures their good solubility in conventional organic solvents, but more importantly successfully tunes their HOMO and LUMO levels into the range of air-stable ambipolar organic semiconductor required on the basis of electrochemical studies over both 1 and 2, meanwhile fine controlling of aggregation mode (H vs. J) in solution-based film for improving OTFT performance is also achieved. Measurements over the OTFT devices fabricated from these sandwich compounds by a solution-based quasi–Langmuir–Shafer (QLS) method reveal their ambipolar semiconductor nature associated with suitable HOMO and LUMO energy levels. Due to the H-aggregation mode employed by the heteroleptic triple-decker molecules in the QLS film, excellent performances with the electron and hole mobility in air as high as 0.68 and 0.014 cm2 V−1 s−1, respectively, have been revealed for the OTFT devices of heteroleptic triple-decker 1. This represents the best performance so far for solution-processable ambipolar single-component phthalocyanine-based OTFTs obtained under ambient conditions. In good contrast, homoleptic analogue 2 prefers to J-type aggregation and this results in relatively lower electron and hole mobility, around 0.041 and 0.0026 cm2 V−1 s−1 in air, respectively, for the devices fabricated. In particular, the performance of the devices fabricated based on 1 was found to remain almost unchanged in terms of both the carrier mobilities and on/off ratio even after being stored under ambient for 4 months.
Mei Liangmo - One of the best experts on this subject based on the ideXlab platform.
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oxide magnetic Semiconductors Materials properties and devices
Chinese Physics B, 2013Co-Authors: Tian Yufeng, Hu Shujun, Yan Shishen, Mei LiangmoAbstract:We give a brief introduction to the oxide (ZnO, TiO2, In2O3, SnO2, etc.)-based magnetic Semiconductors from fundamental material aspects through fascinating magnetic, transport, and optical properties, particularly at room temperature, to promising device applications. The origin of the observed ferromagnetism is also discussed, with a special focus on first-principles investigations of the exchange interactions between transition metal dopants in oxide-based magnetic Semiconductors.
Bakhtiar Ul Haq - One of the best experts on this subject based on the ideXlab platform.
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first principles investigations of mn doped zinc blende zno based magnetic Semiconductors Materials for spintronic applications
Materials Science in Semiconductor Processing, 2015Co-Authors: Bakhtiar Ul Haq, Rashid Ahmed, A Shaari, A Afaq, Bashir Ahmed Tahir, R KhenataAbstract:Abstract ZnO based magnetic Semiconductors are intensively investigated because of showing strong potential as base Materials for spintronic devices. In this study, full potential linearized augmented plane-wave plus local orbitals FP-L(APW+lo) scheme of computation is used to explore the structural, electronic and magnetic properties of Manganese-doped ZnO based magnetic Semiconductors in zinc-blende (ZB) phase. For comprehensive understanding of Mn-doping effect on ZnO, several compositions of Mn:ZnO for 12.5%, 25%, 37.5%, 50%, 62.5%, 75% and 87.5% of Mn concentration are investigated. Our obtained results show a successful induction of the magnetic moment (MM) by Mn-doping into the ZnO matrix, without any geometrical deformation. However a marginal increase in the value of lattice constants is found up to 25% concentration of Mn for this system and for above compositions, it tends to decrease revealing the formation of secondary phases. It is also found that Mn:ZnO system favors ferromagnetic coupling for 12.5% and 25% of Mn contents that has been switched to anti-ferromagnetic coupling for higher Mn contents. The spin polarized electronic structure of Mn:ZnO system was calculated within the generalized gradient approximation (GGA). In addition, the Hubbard parameter was also employed to improve the electronic band structure calculations. The calculations performed at GGA+U level related to electronic band structures show zero energy gap for majority spin carriers, whereas a considerable energy gap is noted for minority spin carriers. This distinguished response of Mn:ZnO system to majority and minority spin carriers, in terms of resistivity and conductivity, highlights its importance for diverse applications as based material in spintronic devices like spin dependent transports, currents and other spin based electronic applications.
