修车大队一品楼qm论坛51一品茶楼论坛,栖凤楼品茶全国楼凤app软件 ,栖凤阁全国论坛入口,广州百花丛bhc论坛杭州百花坊妃子阁

oe1(光电查) - 科学论文

过滤筛选

出版时间
  • 2018
研究主题
  • electron-transparent membranes
  • micropump
  • field emission electron source
  • ion source
  • ion mobility spectrometry
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • Wroclaw University of Science and Technology
209 条数据
?? 中文（中国） ▾

  • Highly Promoted Carrier Mobility and Intrinsic Stability by Rolling Up Monolayer Black Phosphorus into Nanoscrolls

    摘要： Rolling up two-dimensional (2D) materials into nanoscrolls could not only retain the excellent properties of their 2D hosts, but also display intriguing physical and chemical properties that arise from their 1D tubular structures. Here, we report a new class of black phosphorus nanoscrolls (bPNSs), which are stable at room-temperature and energetically more favorable than 2D bP. Most strikingly, these bPNSs hold tunable direct band gaps and extremely high mobilities (e.g., the mobility of the double-layer bPNS is about 20-fold higher than that of 2D bP monolayer). Their unique self-encapsulation structure and layer-dependent conduction band minimum can largely prevent the entering of O2 and the production of O?2 and thereby suppress the possible environmental degradation as well. The enhanced intrinsic stability and promoted electronic properties render bPNSs great promise in many advanced electronics or optoelectronics applications.

    关键词： optoelectronic applications,black phosphorus nanoscrolls,carrier mobility,intrinsic stability,electronic properties

    更新于2025-09-09 09:28:46

  • RF Performance of Al0.85Ga0.15N/Al0.70Ga0.30N High Electron Mobility Transistors with 80 nm Gates

    摘要： Al-rich AlGaN-channel high electron mobility transistors (HEMTs) with 80 nm long gates and 85% (70%) Al in the barrier (channel) were evaluated for RF performance. DC characteristics include a maximum current of 160 mA/mm with transconductance of 24 mS/mm, limited by source and drain contacts, and an on/off current ratio of 109. fT of 28.4 GHz and fMAX of 18.5 GHz were determined from small-signal S-parameter measurements. Output power density of 0.38 W/mm was realized at 3 GHz in a power sweep using on-wafer load pull techniques.

    关键词： high electron mobility transistor,Ultra-wide-bandgap,RF performance,HEMT,aluminum gallium nitride

    更新于2025-09-09 09:28:46

  • High-mobility material research for thin-film transistor with amorphous thallium–zinc–tin oxide semiconductor

    摘要： The applicability of thallium–zinc–tin oxide (TlZnSnO) as a channel material for a thin-?lm transistor (TFT) was investigated by ?rst-principles simulation and cosputtering experiment with XZnSnO (X = Al, Ga or In). The electron effective mass (m*) of Tl0.4ZnSnO was simulated to be >0.153, which is much smaller than that of In0.4ZnSnO (0.246). An In0.4ZnSnO TFT exhibited a mobility (μ) of 32.0 cm2 V%1 s%1 in the experiment; therefore, the Tl0.4ZnSnO TFT was expected to have a higher mobility of approximately 50 cm2 V%1 s%1 following the relation (μ / 1/m*). Moreover, the Tl-related oxide semiconductor would provide better TFT stability because its oxide vacancy is more stable than that of an In-related oxide semiconductor.

    关键词： first-principles simulation,thallium–zinc–tin oxide,mobility,cosputtering,electron effective mass,thin-?lm transistor

    更新于2025-09-09 09:28:46

  • Substrate-Wide Confined Shear Alignment of Carbon Nanotubes for Thin Film Transistors

    摘要： To exploit their charge transport properties in transistors, semiconducting carbon nanotubes must be assembled into aligned arrays comprised of individualized nanotubes at optimal packing densities. However, achieving this control on the wafer-scale is challenging. Here, solution-based shear in substrate-wide, confined channels is investigated to deposit continuous films of well-aligned, individualized, semiconducting nanotubes. Polymer-wrapped nanotubes in organic ink are forced through sub-mm tall channels, generating shear up to 10 000 s?1 uniformly aligning nanotubes across substrates. The ink volume and concentration, channel height, and shear rate dependencies are elucidated. Optimized conditions enable alignment within a ±32° window, at 50 nanotubes μm?1, on 10 × 10 cm2 substrates. Transistors (channel length of 1–5 μm) are fabricated parallel and perpendicular to the alignment. The parallel transistors perform with 7× faster charge carrier mobility (101 and 49 cm2 V?1 s?1 assuming array and parallel-plate capacitances, respectively) with high on/off ratio of 105. The spatial uniformity varies ±10% in density, ±2° in alignment, and ±7% in mobility. Deposition occurs within seconds per wafer, and further substrate scaling is viable. Compared to random networks, aligned nanotube films promise to be a superior platform for applications including sensors, flexible/stretchable electronics, and light emitting and harvesting devices.

    关键词： electronics,alignment,mobility,field-effect transistors,semiconductors

    更新于2025-09-09 09:28:46

  • Creation of Two-Dimensional Electron Gas and Role of Surface Donors in III-N Metal-Oxide-Semiconductor High-Electron Mobility Transistors

    摘要： The role of surface donors at the oxide/semiconductor interface of III-N metal-oxide-semiconductor (MOS) high-electron mobility transistors (HEMTs), by creating a two-dimensional electron gas (2DEG) and the device performance, are investigated. Al2O3/GaN/AlGaN/GaN MOS HEMTs show the surface donor density (Nd,surf ) of 2.2 (cid:1) 1013 cm(cid:3)2 which is increased up to 3.4 (cid:1) 1013 cm(cid:3)2 after post-deposition annealing. In the latter, surface donors fully compensate the surface polarization charge and the HEMT threshold voltage decreases substantially with the oxide thickness. On the other hand, an open-channel drain current is found to be independent of Nd,surf, while marginal trapping is completely removed when Nd,surf increases with annealing. Consequently, ionized surface donors behave like a fixed charge and are clearly distinguishable from trapping states. Open-channel 2DEG densities of (cid:4)1.1 (cid:1) 1013 cm(cid:3)2 are extracted from capacitance–voltage measurements. Similarly, recent data on enhancement-mode HfO2/InAlN/AlN/GaN MOS HEMTs are analyzed where Nd,surf is reduced down to (cid:3)2 while 2DEG densities reach (cid:4)2.7 (cid:1) 1013 cm(cid:3)2. It is suggested that under the open-channel condition, 2DEG is supplied also by an injecting source contact if Nd,surf is lower than the QW polarization charge. Our charge quantifications are supported by calculating energy-band diagrams.

    关键词： oxide-semiconductor interfaces,AlGaN/GaN high-electron mobility transistors (HEMTs),polarization

    更新于2025-09-09 09:28:46

  • Double active layer InZnO:N/InZnSnO thin film transistors with high mobility at low annealing temperature

    摘要： In this paper, bottom-gate top-contact thin film transistors (TFTs) with a double active layer of InZnO:N/InZnSnO (IZO:N/IZTO) were successfully prepared. The IZO:N/IZTO thin films were deposited on SiO2/p-Si substrates by radio frequency (RF) magnetron sputtering at room temperature. The transmittance of both the IZO:N thin film and the IZTO thin film were more than 80% in the range of visible light. The IZO:N thin film and the IZTO thin film were found to be amorphous at the annealing temperature of 325?°C by means of X-ray diffraction (XRD). The double active layer IZO:N/IZTO TFT exhibited good electrical performance with a saturation mobility of 41.5?cm2?V?1?s?1, an on/off current ratio of 2.88 × 105, and a threshold voltage of 1.0?V, which achieved high mobility at the low annealing temperature of 325?°C.

    关键词： low annealing temperature,RF magnetron sputtering,high mobility,InZnO:N/InZnSnO,thin film transistors

    更新于2025-09-09 09:28:46

  • Modifying the electrical properties of graphene by reversible point-ripple formation

    摘要： Strain, ripples and wrinkles in graphene reduce the charge-carrier mobility and alter the electronic behaviour. In few-layer graphene the anisotropy between the in-plane and cross-plane resistivity is altered and a band gap can be opened up. Here we demonstrate a method to reversibly induce point ripples in electrically isolated few-layer graphene with the ability to select the number of layers used for transport measurement down to single layer. During ripple formation the in-plane and cross-plane sheet resistances increase by up to 78% and 699% respectively, confirming that microscopic corrugation changes can solely account for graphene's non-ideal charge-carrier mobility. The method can also count the number of layers in few-layer graphene and is complimentary to Raman spectroscopy and atomic force microscopy when n ≤ 4. Understanding these changes is crucial to realising practical oscillators, nano-electromechanical systems and flexible electronics with graphene.

    关键词： charge-carrier mobility,graphene,electrical properties,flexible electronics,nano-electromechanical systems,point-ripple formation

    更新于2025-09-09 09:28:46

  • Analytical Gate Capacitance Models for Large-Signal Compact Model of AlGaN/GaN HEMTs

    摘要： In this paper, analytical gate capacitance models for a large-signal compact model of AlGaN/GaN high-electron mobility transistors are proposed. Different from the MOSFET devices, different depletion regions on either side of the gate are fully considered for high-voltage GaN devices. The depletion regions are bias-dependent to implement the capacitance models into the large-signal compact model. A transfer function is proposed to characterize the switching behavior of the capacitances between on- and off-states, which is essential to describe all the states of a device, for example, operating at Class-B. Different from previous works, the current saturation phenomenon is taken into account in determining the intrinsic capacitances which are induced by nonstatic channel charge. The capacitance models can be easily implemented into the virtual-source-based model to accurately predict the S-parameters and large-signal output characteristics.

    关键词： intrinsic capacitances,2-D electron gas (2DEG)-electrode fringing capacitances,AlGaN/GaN high-electron mobility transistors (HEMTs),large-signal compact model

    更新于2025-09-09 09:28:46

  • The Effect of Proton Irradiation in Suppressing Current Collapse in AlGaN/GaN High-Electron-Mobility Transistors

    摘要： Almost complete suppression of dynamic ON-resistance in AlGaN/GaN high-electron-mobility transistors is obtained by proton irradiation. In this paper, both small and large power transistors are characterized before and after 3-MeV proton irradiation at different fluences. The irradiated devices show a high robustness and for specific fluences unaltered threshold voltage and static ON-resistance. However, for fluences higher than 1013 cm?2, the dynamic ON-resistance is almost completely suppressed at 600 V and T = 150 °C. After irradiation, a measurable increase in OFF-state leakage current is observed, indicating an increase in the unintentionally doped (UID) GaN layer conductivity. We propose a technology computer-aided design supported model in which this conductivity increase leads to an increased deionization rate, ultimately reducing the dynamic ON-resistance.

    关键词： high-electron-mobility transistor (HEMT),proton irradiation,Gallium nitride (GaN),dynamic ON-resistance

    更新于2025-09-09 09:28:46

  • Hybrid Analog/Digital Linearization of GaN HEMT-Based Power Amplifiers

    摘要： In this paper, we describe a hybrid analog/digital linearization scheme for GaN high-electron-mobility transistor (HEMT)-based power ampli?ers that consists of a novel analog feedforward circuit and a conventional generalized memory polynomial (GMP) digital predistorter (DPD). The analog circuit implements a nonlinear ?lter that compensates the long-term memory effects observed in GaN HEMTs due to the self-biasing behavior caused by electron-trapping phenomena. Experimental tests demonstrate that this linearization scheme achieves a level of intermodulation distortion 6.8 dB better than what can be achieved with just the use of the GMP DPD. This level of distortion is in compliance with the linearity speci?cations for multicarrier Global System for Mobile communications base station transmitters.

    关键词： Analog linearization,long-term memory effects,GaN high-electron-mobility transistor (HEMT),power ampli?er (PA) linearization,digital predistortion (DPD),electron trapping

    更新于2025-09-09 09:28:46