共查询到20条相似文献，搜索用时 15 毫秒
1.
Jiansheng Jie Wenjun Zhang Kuiqing Peng Guodong Yuan Chun Sing Lee Shuit‐Tong Lee 《Advanced functional materials》2008,18(20):3251-3257
Surface effects are widely recognized to significantly influence the properties of nanostructures, although the detailed mechanisms are rarely studied and unclear. Herein we report for the first time a quantitative evaluation of the surface‐related contributions to transport properties in nanostructures by using Si nanowires (NWs) as a paradigm. Critical to this study is the capability of synthesizing SiNWs with predetermined conduction type and carrier concentration from Si wafer of known properties using the recently developed metal‐catalyzed chemical etching method. Strikingly, the conductance of p‐type SiNWs is substantively larger in air than that of the original wafer, is sensitive to humidity and volatile gases, and thinner wires show higher conductivity. Further, SiNW‐based field‐effect transistors (FETs) show NWs to have a hole concentration two orders of magnitude higher than the original wafer. In vacuum, the conductivity of SiNWs dramatically decreases, whereas hole mobility increases. The device performances are further improved by embedding SiNW FETs in 250 nm SiO2, which insulates the devices from atmosphere and passivates the surface defects of NWs. Owing to the strong surface effects, n‐type SiNWs even change to exhibit p‐type characteristics. The totality of the results provides definitive confirmation that the electrical characteristics of SiNWs are dominated by surface states. A model based on surface band bending and carrier scattering caused by surface states is proposed to interpret experimental results. The phenomenon of surface‐dependent transport properties should be generic to all nanoscale structures, and is significant for nanodevice design for sensor and electronic applications. 相似文献
2.
Jiyeon Ma Hyung Jun Cho Junseok Heo Sunkook Kim Geonwook Yoo 《Advanced Electronic Materials》2019,5(6)
The ultra‐wide bandgap and cost‐effective melt‐growth of β‐Ga2O3 ensure its advantages over other wide bandgap materials, and competitive electrical performance has been demonstrated in various device structures. In this paper, an asymmetric double‐gate (ADG) β‐Ga2O3 nanomembrane field‐effect transistor (FET) comprised of a bottom‐gate (BG) metal‐oxide field‐effect transistor and a top‐gate (TG) metal‐semiconductor field‐effect transistor (MESFET) is demonstrated. Schottky contact properties are validated by characterizing the lateral Schottky barrier diode (SBD), which exhibits high rectification ratio and low ideality factor. The top‐gate β‐Ga2O3 MESFET shows reasonable electrical performance with a high breakdown voltage, as anticipated by three terminal off‐state breakdown measurement. These properties are further enhanced by double‐gate operation, and superior device performance is demonstrated; positive‐shifted threshold voltage and reduced subthreshold slope enable the asymmetric double‐gate β‐Ga2O3 FET to operate at low power, and almost twice as much transconductance is demonstrated for high‐frequency operation. These results show the great potential of asymmetric double‐gate β‐Ga2O3 FETs for energy‐efficient high‐voltage and ‐frequency devices with optimal material and structure co‐designs. 相似文献
3.
Tengzhou Yang Qian Wu Fuhua Dai Kairong Huang Huihua Xu Chenning Liu Changdong Chen Sujuan Hu Xiaoci Liang Xuying Liu Yong‐Young Noh Chuan Liu 《Advanced functional materials》2020,30(20)
Many advanced materials have been developed for organic field‐effect transistors (OFETs) or thin‐film transistors (TFTs) based on organic and organic hybrid materials. However, although many new OFETs exhibit superior characteristic parameters (such as high mobility), most of them show nonideal performances that have strongly limited progress in the design of molecules, the understanding of transport mechanisms, and the circuit applications of OFETs. In this review, the device physics of ideal and nonideal OFETs is discussed first to understand the factors that limit effective mobility in semiconducting channels, distort the potential distribution, or reduce the drift electric field. Then, recent advances in optimizing the material combinations, device structures, and fabrications of OFETs toward ideal transistors are discussed. Based on the good control of materials and interfaces, some new and novel concepts to utilize the nonideal properties of OFETs to build low‐power circuits and integrated sensors are also discussed. 相似文献
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5.
Galen L. Eakins Rishi Pandey Jonathan P. Wojciechowski Han Yue Zheng James E. A. Webb Céline Valéry Pall Thordarson Natalie O. V. Plank Juliet A. Gerrard Justin M. Hodgkiss 《Advanced functional materials》2015,25(35):5640-5649
Specific peptide sequences designed by inspection of protein–protein interfaces have been identified and used as tectons in hybrid functional materials. Here, an 8‐mer peptide derived from an interface of the peroxiredoxin family of self‐assembling proteins is exploited to encode the assembly of the perylene imide‐based organic semiconductor building blocks. By augmenting the peptide with additional functionality to trigger aggregation and manipulate the directionality of peptide‐semiconductor coupling, a series of hybrid materials based on the natural peptide interface is presented. Using spectroscopic probes, the mode of self‐assembly and the electronic coupling between neighboring perylene units is shown to be strongly affected by the number of peptides attached, and by their backbone directionality. The disubstituted material with peptides extending in the N to C direction away from the perylene core exhibits strong coupling and long‐range order, both attractive properties for electronic device applications. A bio‐organic field‐effect transistor is fabricated using this material, highlighting the possibilities of exploiting natural peptide tectons to encode self‐assembly in other functional materials and devices. 相似文献
6.
Electroless-plated gold and platinum films are used as source and drain electrodes in high-performance solution-processed organic field-effect transistors (OFETs), representing a promising large-area, near-room-temperature and vacuum-free technique to form low-resistance metal-to-semiconductor interfaces in ambient atmosphere. Developing non-displacement conditions using a Pt-colloidal catalyst for soft electroless plating, the electrodes are deposited on crystallized thin films of 2,9-didecyl-dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene (C10-DNTT) without significant damage to the semiconductor material. The top-contact OFETs show remarkable performance, with a mobility of 6.0 cm2 V?1 s?1. The method represents a practical fabrication technique to mass-produce circuitry arrays of nearly best-performing OFETs for the printed electronics industry. 相似文献
7.
用非平衡格林函数方法研究一种自旋场效应晶体管的电子输运特性。结果表明,不考虑自旋散射的作用,当漏极电压比较小时该器件能达到很高的磁阻比率。对该器件在考虑自旋散射和不考虑自旋散射下的输出电流进行对比,发现在铁磁平行(反平行)的条件下,考虑自旋散射时的输出电流要比不考虑自旋散射时的输出电流小(大)。研究结果揭示了该器件的物理机制,为该器件的优化设计提供了理论指导。 相似文献
8.
Alasdair J. Campbell Ruth Rawcliffe Alexander Guite Jorge Costa Dantas Faria Abhimanyu Mukherjee Martyn A. McLachlan Maxim Shkunov Donal D. C. Bradley 《Advanced functional materials》2016,26(21):3720-3729
A charge‐carrier density dependent mobility has been predicted for amorphous, glassy energetically disordered semiconducting polymers, which would have considerable impact on their performance in devices. However, previous observations of a density dependent mobility are complicated by the polycrystalline materials studied. Here charge transport in field‐effect transistors and diodes of two amorphous, glassy fluorene‐triarylamine copolymers is investigated, and the results explored in terms of a charge‐carrier density dependent mobility model. The nondispersive nature of the time‐of‐flight (TOF) transients and analysis of dark injection transient results and transistor transfer characteristics indicate a charge‐carrier density independent mobility in both the low‐density diode and the high‐density transistor regimes. The mobility values for optimized transistors are in good agreement with the TOF values at the same field, and both have the same temperature dependency. The measured transistor mobility falls two to three orders of magnitude below that predicted from the charge‐carrier density dependent model, and does not follow the expected power‐law relationship. The experimental results for these two amorphous polymers are therefore consistent with a charge‐carrier density independent mobility, and this is discussed in terms of polaron‐dominated hopping and interchain correlated disorder. 相似文献
9.
Illhun Cho Sang Kyu Park Boseok Kang Jong Won Chung Jin Hong Kim Kilwon Cho Soo Young Park 《Advanced functional materials》2016,26(17):2966-2973
A series of indolo[3,2‐b]indole (IDID) derivatives comprising the core unit of N,N‐dihexyl‐IDID with different aromatic and aliphatic substituents at 2‐ and 7‐position are designed and synthesized to construct high‐performance organic semiconductors by different processing routes. Structure‐property relationship of the derivatives is comprehensively studied in terms of their photophysical, electrochemical, structural, and electrical characteristics. IDID derivatives are either evaporated in vacuum or dissolved in common organic solvents to ensure applicalbility in different processing routes toward outstanding p‐type semiconductor films. Among others, the excellently soluble compound 4H4TIDID (with 2‐ and 7‐substituents of 5‐hexyl‐2,2′‐bithiophene moiety, solubility >20 wt% in chloroform), shows the highest field‐effect hole mobility of 0.97 cm2 V?1 s?1 in a device constructed by vacuum‐deposition and 0.18 cm2 V?1 s?1 in device cosntructed by spin‐coating, respectively. The 2D grazing incidence X‐ray diffraction of 4H4TIDID films in both devices identically show the 2D molecular orientation favorable for the high transistor mobility. 相似文献
10.
采用量子输运模型和NEGF理论,自洽求解薛定谔方程和泊松方程,对类MOS-碳纳米管场效应晶体管的电子输运特性建模。考察了沟道长度Lg为5~25 nm时,其对器件的导通电流、阈值电压、关态泄漏电流、电流开关比、亚阈值摆幅等性质的影响。结果表明:当Lg≥15 nm时,MOS-CNTFET没有量子尺寸效应;当Lg<15 nm时,器件出现短沟道效应;Lg<10 nm时短沟道效应更加明显。 相似文献
11.
Soohwan Jang F. Ren S. J. Pearton B. P. Gila M. Hlad C. R. Abernathy Hyucksoo Yang C. J. Pan Jenn-Inn Chyi P. Bove H. Lahreche J. Thuret 《Journal of Electronic Materials》2006,35(4):685-690
Si diffusion into GaN was studied as a function of encapsulant type (SiO2 or SiNx) and diffusion temperature. Using a SiO2 encapsulant, the Si diffusion exhibited an activation energy of 0.57 eV with a prefactor of 2.07×10−4 cm2 sec−1 in the temperature range 800–1,000°C. An enhancement-mode MgO/GaN-on-Si metal-oxide semiconductor field-effect transistor (MOSFET) was fabricated utilizing Si-diffused regions under the source and drain to provide an accumulated channel. The gate leakage through the undoped GaN was low enough for us to achieve good saturation behavior in the drain-current-voltage characteristics. The devices showed improved transconductance and drain current relative to previous devices with Si-implanted source/drain regions. 相似文献
12.
Arun Kumar Singh Shaista Andleeb Jai Singh Hoang Tien Dung Yongho Seo Jonghwa Eom 《Advanced functional materials》2014,24(45):7125-7132
The tuning of charge carrier concentrations in semiconductor is necessary in order to approach high performance of the electronic and optoelectronic devices. It is demonstrated that the charge‐carrier density of single‐layer (SL), bilayer (BL), and few‐layer (FL) MoS2 nanosheets can be finely and reversibly tuned with N2 and O2 gas in the presence of deep‐ultraviolet (DUV) light. After exposure to N2 gas in the presence of DUV light, the threshold voltages of SL, BL, and FL MoS2 field‐effect transistors (FETs) shift towards negative gate voltages. The exposure to N2 gas in the presence of DUV light notably improves the drain‐to‐source current, carrier density, and charge‐carrier mobility for SL, BL, and FL MoS2 FETs. Subsequently, the same devices are exposed to O2 gas in the presence of DUV light for different periods and the electrical characteristics are completely recovered after a certain time. The doping by using the combination of N2 and O2 gas with DUV light provides a stable, effective, and facile approach for improving the performance of MoS2 electronic devices. 相似文献
13.
《Advanced Electronic Materials》2018,4(3)
Lead chalcogenides with large exciton Bohr radius display strong quantum confinement, which make them applicable in a wide range of optoelectronic devices such as solar cells and photodetectors. Especially, 1D PbSe nanocrystals attract much attention with their potential for multiple exciton generation. However, very little is known on their charge transport properties. In this study well performing field‐effect transistors based on PbSe nanorods with an inorganic iodide‐based ligand are presented for the first time. The transistors at room temperature display ambipolar characteristics with electron mobility of ≈0.1 cm2 V−1 s−1 and hole mobility of 1.1 × 10−4 cm2 V−1 s−1 in the ultraclean environment. Low temperature investigation reveals a transition around 200 K between nearest‐neighbor and variable‐range hopping mechanism. Below 200 K, the transport properties are dominated by the severe disorder. 相似文献
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15.
Fengjiao Zhang Yaping Zang Dazhen Huang Chong‐an Di Xike Gao Henning Sirringhaus Daoben Zhu 《Advanced functional materials》2015,25(20):3004-3012
Organic thermoelectric materials, which can transform heat flow into electricity, have great potential for flexible, ultra‐low‐cost and large‐area thermoelectric applications. Despite rapid developments of organic thermoelectric materials, exploration and investigation of promising organic thermoelectric semiconductors still remain as a challenge. Here, the thermoelectric properties of several p‐ and n‐type organic semiconductors are investigated and studied, in particular, how the electric field modulations of the Seebeck coefficient in organic field‐effect transistors (OFETs) compare with the Seebeck coefficient in chemically doped films. The extracted relationship between the Seebeck coefficient (S) and electrical conductivity (σ) from the field‐effect transistor (FET) geometry is in good agreement with that of chemically doped films, enabling the investigation of the trade‐off relationship among σ, S, carrier concentration, and charging level. The results make OFETs an effective candidate for the thermoelectric studies of organic semiconductors. 相似文献
16.
We have investigated the 20 nm p-type double gate junctionless tunnel field effect transistor （P-DGJLTFET） and the impact of variation of different device parameters on the performance parameters of the P-DGJLTFET is discussed. We achieved excellent results of different performance parameters by taking the optimized device parameters of the P-DGJLTFET. Together with a high-k dielectric material （TiO2） of 20 nm gate length, the simulation results of the P-DGJLTFET show excellent characteristics with a high IoN of ～ 0.3 mA/μm, a low/OFF of ～ 30 fA/μm, a high ION/IOFF ratio of ～ 1×10^10, a subthreshold slope （SS） point of ～ 23 mV/decade, and an average SS of ～ 49 mV/decade at a supply voltage of -1 V and at room temperature, which indicates that PDGJLTFET is a promising candidate for sub-22 nm technology nodes in the implementation of integrated circuits. 相似文献
17.
Subthreshold characteristics of vertical tunneling field effect transistors(VTFETs) with an nC-pocket in the pC-source are studied by simulating the transfer characteristics with a commercial device simulator.Three types of subthreshold characteristics are demonstrated for the device with different pocket thicknesses and doping concentrations.Band diagram analysis shows that such a VTFET can be treated as a gate-controlled tunnel diode connected in series with a conventional n-channel metal-oxide-semiconductor FET.This VTFET can work either as a TFET or an n-MOSFET in the subthreshold region,depending on the turn-on sequence of these two components.To our knowledge,this is the first time such a device model has been used to explain the subthreshold characteristics of this kind of VTFET and the simulation results demonstrate that such a device model is convictive and valid.Our results indicate that the design of the nC pocket is crucial for such a VTFET in order to achieve ultra-steep turn-on characteristics. 相似文献
18.
For the first time, we investigate the analog performance of n-type double gate junctionless tunnel field effect transistor （DG-JLTFET） and the results are compared with the conventional n-type double gate tunnel field effect transistor （DG-TFET） counterpart. Using extensive device simulations, the two devices are compared with the following analog performance parameters, namely transconductance, output conductance, output resistance, intrinsic gain, total gate capacitance and unity gain frequency. From the device simulation results, DG-JLTFET is found to have significantly better analog performance as compared to DG-TFET. 相似文献
19.
Peng Yu Xuechao Yu Wanglin Lu Hsin Lin Linfeng Sun Kezhao Du Fucai Liu Wei Fu Qingsheng Zeng Zexiang Shen Chuanhong Jin Qi Jie Wang Zheng Liu 《Advanced functional materials》2016,26(1):137-145
Atomically layered 2D crystals such as transitional metal dichalcogenides (TMDs) provide an enchanting landscape for optoelectronic applications due to their unique atomic structures. They have been most intensively studied with 2H phase for easy fabrication and manipulation. 1T phase material could possess better electrocatalytic and photocatalytic properties, while they are difficult to fabricate. Herein, for the first time, the atomically layered 1T phase tin diselenides (SnSe2, III‐IV compound) are successfully exfoliated by the method of mechanical exfoliation from bulk single crystals, grown via the chemical vapor transport method without transport gas. More attractively, the high performance atomically layered SnSe2 photodetector has been first successfully fabricated, which displays a good responsivity of 0.5 A W?1 and a fast photoresponse down to ≈2 ms at room temperature, one of the fastest response times among all types of 2D photodetectors. It makes SnSe2 a promising candidate for high performance optoelectronic devices. Moreover, high performance bilayered SnSe2 field‐effect transistors are also demonstrated with a mobility of ≈4 cm2 V?1 s?1 and an on/off ratio of 103 at room temperature. The results demonstrate that few layered 1T TMD materials are relatively stable in air and can be exploited for various electrical and optical applications. 相似文献
20.
Chuming Sheng Xinyu Wang Xiangqi Dong Yan Hu Yuxuan Zhu Die Wang Saifei Gou Qicheng Sun Zhejia Zhang Jinshu Zhang Mingrui Ao Haojie Chen Yuchen Tian Jieya Shang Yufei Song Xinliu He Zihan Xu Lin Li Peng Zhou Wenzhong Bao 《Advanced functional materials》2024,34(29):2400008
2D semiconductors have emerged as candidates for next-generation electronics. However, previously reported 2D transistors which typically employ the gate-first process to fabricate a back-gate (BG) configuration while neglecting the thorough impact on the dielectric capping layer, are severely constrained in large-scale manufacturing and compatibility with complementary metal–oxide–semiconductor (CMOS) technology. In this study, dual-gate (DG) field-effect transistors have been realized based on wafer-scale monolayer MoS2 and the gate-last processing, which avoids the transfer process and utilizes an optimized top-gate (TG) dielectric stack, rendering it highly compatible with CMOS technology. Subsequently, the physical mechanism of TG dielectric deposition and the corresponding controllable threshold voltage (VTH) shift is investigated. Then the fabricated TG-devices with a large on/off ratio up to 1.7 × 109, negligible hysteresis (≈14 mV), and favorable stability. Additionally, encapsulated TG structured photodetectors have been demonstrated which exhibit photo responsivity (R) up to 9.39 × 103 A W−1 and detectivity (D*) ≈2.13 × 1013 Jones. The result paves the way for future CMOS-compatible integration of 2D semiconductors for complex multifunctional IC applications. 相似文献