- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Evaluating glucose and mannose profiles in Candida species using quantum dots conjugated with Cramoll lectin as fluorescent nanoprobes
摘要： Glycoconjugates found on cell walls of Candida species are fundamental for their pathogenicity. Laborious techniques have been employed to investigate the sugar composition of these microorganisms. Herein, we prepared a nanotool, based on the fluorescence of quantum dots (QDs) combined with the specificity of Cramoll lectin, to evaluate glucose/mannose profiles on three Candida species. The QDs-Cramoll conjugates presented specificity and bright fluorescence emission. The lectin preserved its biological activity after the conjugation process mediated by adsorption interactions. The labeling of Candida species was analyzed by fluorescence microscopy and quantified by flow cytometry. Morphological analyses of yeasts labeled with QDs-Cramoll conjugates indicated that C. glabrata (2.7 μm) was smaller when compared to C. albicans (4.0 μm) and C. parapsilosis sensu stricto (3.8 μm). Also, C. parapsilosis population was heterogeneous, presenting rod-shaped blastoconidia. More than 90% of cells of the three species were labeled by conjugates. Inhibition and saturation assays indicated that C. parapsilosis had a higher content of exposed glucose/mannose than the other two species. Therefore, QDs-Cramoll conjugates demonstrated to be effective fluorescent nanoprobes for evaluation of glucose/mannose constitution on the cell walls of fungal species frequently involved in candidiasis.
关键词： Candida,Cratylia mollis,Bioconjugation,Semiconductor nanocrystals,Lectin
更新于2025-09-11 14:15:04
-
Tuning Spontaneous Emission through Waveguide Cavity Effects in Semiconductor Nanowires
摘要： The ability to tailor waveguide cavities and couple them with quantum emitters has developed a realm of nano-photonics encompassing, for example, highly efficient single photon generation or the control of giant photon nonlinearities. Opening new grounds by pushing the interaction of the waveguide cavity and integrated emitters further into the deep subwavelength regime, however, has been complicated by nonradiative losses due to the increasing importance of surface defects when decreasing cavity dimensions. Here, we show efficient suppression of nonradiative recombination for thin waveguide cavities using core?shell semiconductor nanowires. We experimentally reveal the advantages of such nanowires, which host mobile emitters, that is, free excitons, in a one-dimensional (1D) waveguide, highlighting the resulting potential for tunable, active, nanophotonic devices. In our experiment, controlling the nanowire waveguide diameter tunes the luminescence lifetime of excitons in the nanowires across 2 orders of magnitude up to 80 ns. At the smallest wire diameters, we show that this luminescence lifetime can be manipulated by engineering the dielectric environment of the nanowires. Exploiting this unique handle on the spontaneous emission of mobile emitters, we demonstrate an all-dielectric spatial control of the mobile emitters along the axis of the 1D nanowire waveguide.
关键词： Semiconductor nanowire,free excitons,photonic waveguide cavity,subwavelength nanophotonics,luminescence lifetime,tunable spontaneous emission
更新于2025-09-11 14:15:04
-
Overview of Recent Progress of Semiconductor Power Devices based on Wide Bandgap Materials
摘要： Wide bandgap materials, which have shown superior material properties, such as better thermal conductivity and excellent electric performance, have aroused wide concern from scientists and engineers. Currently, research towards semiconductor power devices based on wide bandgap materials has made great achievements. The new developed WBG (wide bandgap) power devices, such as 1200V Direct-Driven SiC JFET power switch and highly reliable GaN MOS HFET displayed better performances and advantages, comparing to traditional Si based power devices. These power devices have been widely used in variety of applications with its successful commercialization, which convincingly proved their reliability and effectiveness. The usage of WBG power devices greatly improved the circuit performance, contributed to the evolve of the new generation electric products. In this paper, we mainly focus on introducing recent progresses and research results of several type of power devices based on WBG materials, including GaN, IGBT, JFET, MOSFET, rectifiers and their SiC counterparts. Their characteristics, performances and relevant applications will be discussed and compared respectively. Then, some deficiency and limits of these devices, as well as solutions of these defects will be illustrated. Finally, future developments and prospects of WBG power devices will be analyzed.
关键词： rectifiers,GaN,IGBT,MOSFET,wide bandgap materials,SiC,JFET,semiconductor power devices
更新于2025-09-11 14:15:04
-
High-performance Zinc-Tin-Oxide thin film transistors based on environment friendly solution process
摘要： Zinc-Tin-Oxide (ZTO) thin films were fabricated using a simple and eco-friendly sol-gel method and their application in thin film transistors (TFTs) was investigated. Annealing temperature has a crucial influence on the structure and electrical properties of sol-gel ZTO thin films. The ZTO thin films annealed at 300-600 (cid:1) revealed smooth and uniform surfaces with amorphous state, in addition, a high optical transparency over 90% of the ZTO films in the visible range was obtained. The electrical performance of ZTO TFTs showed obvious dependence on annealing temperature. The ZTO TFTs annealed at 500 (cid:1) showed a high carrier mobility of 5.9 cm2/Vs, high on/off current ratio (Ion/off) of 106-107, and threshold voltage (Vth) of 1.03V. To demonstrate the application of sol-gel ZTO films in low-power display fields, we also fabricated ZTO TFTs with a solution-processed high-permittivity (high-k) ZrTiOx dielectric layer. The ZTO/ ZrTiOx TFTs showed high mobility of 17.9 cm2/Vs and Ion/off of 105-106 at a low operation voltage of 3 V, indicating that Indium-free ZTO thin films would be potential candidates for low cost, high performance oxide TFT devices.
关键词： oxide semiconductor,sol-gel process,thin-film transistor
更新于2025-09-11 14:15:04
-
Subfemtosecond charge driving with correlation-assisted band engineering in a wide-gap semiconductor
摘要： First-principles calculations indicate that, before falling into dielectric breakdown, charge transport induced by a strong-intensity few-cycle optical waveform in the subfemtosecond time domain can be precisely controlled depending on band distortion engineered by strain along the [0001] direction in wurtzite-AlN. It is further discovered from a model of electron-hole interaction that the subfemtosecond charge driving with band engineering can be substantially strengthened by excitonic correlation and dynamics. With these findings, we reveal band engineering to be a route to the ultrafast charge control of semiconductors and indeed suggest an unexplored prototype of solid-state petahertz (1015 Hz) device.
关键词： petahertz device,subfemtosecond charge driving,exciton correlation,wide-gap semiconductor,band engineering
更新于2025-09-11 14:15:04
-
Modulation Effects on Power-loss and Leakage Current in Three-Phase Solar Inverters
摘要： Three-phase solar inverters can be operated with different modulation strategies such as sinusoidal pulse-width modulation (SPWM), space vector modulation (SVM), third-harmonic injection PWM (THIPWM). The selection of the modulation strategy can significantly affect PV leakage currents and power losses and compromise the inverter performance. This paper presents a detailed analysis of traditional and modified modulation effects on power semiconductor losses and photovoltaic (PV) leakage current. The research focuses on a three-phase Three-Level T-type Neutral Point Clamped (3L-TNPC) solar inverter. A detailed exploration of traditional SPWM and SVM is presented and a new modified modulation strategy referred to as two-triplen harmonic injection PWM (2THIPWM) which can substitute the SVM scheme. Analytical expressions are derived for the proposed 2THIPWM strategy which can be used for the SVM power-loss approximation. The comparison between 2THIPWM and SPWM shows a conduction-loss difference greater than the 5% normalized range. The modulation strategies are discussed with respect to the PV common mode current signature and specific design techniques in modulation lead to reduced leakage currents for safety compliance. The theoretical and experimental results obtained using a 3L-TNPC solar inverter are presented to evaluate the modulation strategies and their impact on performance.
关键词： three-phase modulation,PV leakage current,Three-phase three-level (3L) TNPC power semiconductor losses
更新于2025-09-11 14:15:04
-
Metal Capping on Silicon Indium Zinc Oxide Semiconductor for High Performance Thin Film Transistors Processed at 150 °C
摘要： We fabricated amorphous silicon-indium-zinc-oxide (a-SIZO) thin film transistors (TFTs) by RF sputtering at the low processing temperature of 150 °C. Metal capping (MC) structure on TFTs showed enhanced performance. Even at low annealing temperature, the field-effect mobility (μFE) showed 21.4 cm2/V s, and Vth shift was only 1.3 V. We attribute the enhancement of mobility to the metal capping layer, which effectively prevents the ambient effect of hydrogen and water vapor.
关键词： SiInZnO,Metal Capping,Thin Film Transistors,Oxide Semiconductor
更新于2025-09-11 14:15:04
-
Local valence electronic states of silicon (sub)oxides on HfO2/Si-(sub)oxide/Si(110) and HfSi2/Si-(sub)oxide/Si(110) Islands
摘要： The effect on the local valence electronic states of Sin+ suboxide components (n = 2, 3, and 4) of hafnium deposited on a low-index Si(110) substrate is investigated by Si-L23VV Auger electron Sin+-2p photoelectron coincidence spectroscopy (Si-L23VV-Sin+-2p APECS), and the chemical states and stabilities are discussed. Hafnium-covered Si(110) is immediately oxidized to HfO2 and SiO2 because hafnium serves as an effective catalyst for Si oxidation. Therefore, a HfO2/Sin+-(sub)oxide/Si(110) [HfO2/Sin+/Si(110)] structure is easily formed (n = 1, 2, 3, and 4). Oxygen diffusion from HfO2 layers toward the Si(110) substrate is promoted by annealing at 923 K. Oxygen atom desorption from the HfO2/Sin+/Si(110) surface occurs after annealing at 1073 K, and HfSi2 islands (i-HfSi2) are formed with a partly exposed Si(110)-16 × 2 double domain (DD) surface. i-HfSi2 shows low reactivity toward O2 molecules, whereas the exposed Si(110)-16 × 2 DD surface is immediately oxidized. Here, a i-HfSi2/Sin+-(sub)oxide/Si(110) structure is formed. Furthermore, we measure the Si-L23VV-Sin+-2p APECS spectra of Sin+ in the HfO2/Sin+/Si(110) and the i-HfSi2/Sin+/Si(110) structures (n = 2, 3, and 4) to evaluate the local valence electronic states of the Sin+ (sub)oxide components. The binding energy at the valence band maximum (BEVBM) of Sin+ in the i-HfSi2/Sin+/Si(110) structure is lower than 1.5 ± 0.7 eV as compared to that in the HfO2/Sin+/Si(110) structure (n = 2, 3, and 4). The local valence electric states of the nearest neighbors and the second neighbors through oxygen of Sin+ are determined to affect those of the Sin+ atom (n = 2, 3, and 4). The Sin+ atoms in the i-HfSi2/Sin+/Si(110) structure can directly bond to hafnium atoms as the nearest neighbors and most commonly have Sim+ atoms in lower ionic valence states as second neighbors (m < 4), whereas the Sin+ atoms in the HfO2/Sin+/Si(110) structure cannot form this bond. In addition, the existence of Hf silicide and Si in lower ionic valence states can reduce the band gap of the HfO2/Si(110) structure.
关键词： High-dielectric-constant material,X-ray photoelectron spectroscopy,Local valence electronic states at surface and interface,Synchrotron radiation,Auger photoelectron coincidence spectroscopy,Metal-insulator-semiconductor structure
更新于2025-09-11 14:15:04
-
Hybrid Metal-Semiconductor Meta-Surface Based Photo-Electronic Perfect Absorber
摘要： Metal films and semiconductor materials have been utilized for numerous optoelectronic devices due to the impressive electrical features. Nevertheless, the feasible way for achieving light anti-reflection or perfect absorption from opaque metal films and high-index semiconductors has not been established yet. In this work, we numerically propose and demonstrate a new functional metal-semiconductor slab, which can produce perfect light absorption in the optical range. High-index semiconductor resonators have been used to provide strong optical field coupling with the incident light. For the Ag-Si resonant slab consisting of a silicon rings array in the Ag slab, dual-band light absorption with the absorption efficiency above 99% is achieved due to the hybridized coupling of photonic and plasmonic modes for the Si and Ag resonators. Additionally, tri-band light absorption can be obtained when a paired silicon rings array is used. Moreover, these absorption properties can be spectrally manipulated via tuning the structural parameters. Furthermore, the absorber scheme is observed to be realizable by other metals and semiconductors. These optical and structural features can not only provide alternative ways for multi-band light absorption but also suggest new insight on the functional optoelectronics such as the infrared photo-detectors, hot-electron excitation and nonlinear optics.
关键词： meta-surface,plasmonic,hybrid metal-semiconductor,perfect absorber
更新于2025-09-11 14:15:04
-
CH <sub/>4</sub> Concentration Distribution in a Semiconductor Process Chamber Measured by the CT-TDLAS
摘要： We measured methane (CH4) concentration distribution in a semiconductor process chamber by using the computed tomography-tunable diode laser spectroscopy (CT-TDLAS). We designed the CT-TDLAS measurement system with a 32-laser-path. The CH4 concentration distribution was measured by the CT-TDLAS based on the 32 absorption spectra which were collected by scanning the laser wavelength around the CH4 absorption peak of 1653.7 nm. We checked linearity of the measurement, validity of the algorithm, and resolution of the computed tomography (CT) reconstructed distribution. In the algorithm check, we measured a simple concentration distribution generated in a ?ve-fold concentric cylinder. Next, we designed a semiconductor process chamber in which the 32-laser-path was installed. After quantitative evaluations of the CT reconstructed distributions by comparing the simulated results of computational ?uid dynamics, we actually measured the CH4 concentration distribution in the chamber when we streamed 10% CH4 from one of four inlet ports and nitrogen from other three ports into the chamber. The measured distributions were obviously different in accordance with the CH4 inlet location, although all the inlet ports were located cyclic-symmetrically. Those results indicated that the ?ow impedances of the four exhaust holes on the susceptor were different depending their locations.
关键词： computed tomography,semiconductor process chamber,CT-TDLAS,methane concentration distribution,tunable diode laser spectroscopy
更新于2025-09-11 14:15:04