- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Analytical model for accurate extraction of metal-semiconductor ohmic contact parameters using a novel electrode-pair layout scheme
摘要： In this paper, an electrode-pair model is proposed and demonstrated for the first time to accurately extract the electrical resistance parameters of the planar metal-semiconductor ohmic contacts. Different from the conventional transmission line model, the proposed model layout features a series of separated electrode pairs with the same electrode distance but various widths. Meanwhile, an equivalent circuit for contact resistance composition is set up to clearly specify the contribution of each resistance component to the overall contact performance. The semiconductor sheet resistances underneath the contact and outside the contact area are treated as completely independent variables. The proposed scheme is modeled theoretically and analyzed by the TCAD simulations, and the validity of the model is verified by the experimental data. Finally, the variance of the sheet resistance underneath the contact after annealing treatment can be distinguished by the model and hence more actual and precise specific contact resistance is achieved. This work provides a distinct perspective to understand and quantify the electrical characteristics of the semiconductor ohmic contacts, and it can also assist engineers for a better electrode layout design.
关键词： Ohmic contacts,Gallium Nitride,Semiconductor devices,Modeling process
更新于2025-09-10 09:29:36
-
Water-based Terahertz Metamaterial for Skin Cancer Detection Application
摘要： We present a highly sensitive detection of skin cancer using a novel water-based (THz) metamaterial (MM) used semiconductor film. We apply the application of terahertz pulsed imaging (TPI) in reflection geometry for the study of skin tissue and related cancers. As a refractive index (RI) sensing application of the proposed device, there will be shown with placing different sensing materials in the biosensor design, the effective RI will also change that in turn leads to measuring the sensitivity of the biosensor to detect the normal skin and Basal Cell Carcinoma (BCC). The RI FOM value of the proposed device is much higher than for the sensor using semiconductor film, to detect biomarkers in the literature. Significantly, the sensitivity increases by about 117 um/RIU and the RI FOM increases by more than 20.53. This results from a combination of size-related factors, leading to field enhancement accompanying strong field localization. We observed the resonance-frequency shift of the THz MM following the RI changing of the detected skin. The dip reflectance resonance has a blue-shift for normal skin. Finally, we suggest that this water-based MM can be used to control of the gene expression. The advantage of our design depends on two factors. Firstly, we used the MM structure, which has micro-scale, and the smaller the size of the structure, the more sensitive to the changes in the RI. Secondly, we used water in our structure, which is very well-suited to the human body and are highly bio-absorbable and inexpensive which is abundantly found in nature.
关键词： bio-absorbable metamaterials,Skin Cancer detection,THz Metamaterials,Semiconductor Biosensor,Refractive Index Sensor,control of the gene expression
更新于2025-09-10 09:29:36
-
A fast quantum interface between different spin qubit encodings
摘要： Single-spin qubits in semiconductor quantum dots hold promise for universal quantum computation with demonstrations of a high single-qubit gate fidelity above 99.9% and two-qubit gates in conjunction with a long coherence time. However, initialization and readout of a qubit is orders of magnitude slower than control, which is detrimental for implementing measurement-based protocols such as error-correcting codes. In contrast, a singlet-triplet qubit, encoded in a two-spin subspace, has the virtue of fast readout with high fidelity. Here, we present a hybrid system which benefits from the different advantages of these two distinct spin-qubit implementations. A quantum interface between the two codes is realized by electrically tunable inter-qubit exchange coupling. We demonstrate a controlled-phase gate that acts within 5.5 ns, much faster than the measured dephasing time of 211 ns. The presented hybrid architecture will be useful to settle remaining key problems with building scalable spin-based quantum computers.
关键词： spin qubits,quantum computation,controlled-phase gate,semiconductor quantum dots,singlet-triplet qubit
更新于2025-09-10 09:29:36
-
Reference Module in Chemistry, Molecular Sciences and Chemical Engineering || Aryl–Aryl Coupling on Semiconductor Surfaces
摘要： Bottom-up strategies in nanotechnology offer unprecedented precision in fabrication of functional structures and devices. Soon after the advent of scanning probe microscopies in the 1980s, it was demonstrated that on-surface nanoobjects may be constructed at ultimate level of control—one atom at a time. Later on, it was shown that even a chemical reaction between two molecular entities is manageable in a stepwise fashion—all steps of a chemical reaction may be induced with scanning tip at will. The limits of precision have been reached. If one considers practical implementations, however, a major obstacle of tip-induced processes appears to be their tediousness. Alternative, fast, yet, precise routes to nanostructure formation are sought. In such a context non-locally induced procedures seem to be especially rewarding. There are, still, at least two expectations with regard to nonlocally induced chemical reactions. First, there is a need for a kind-of-trigger that will allow for a controlled activation of a given procedure. Second, it would be beneficial if the whole process is controllable by means of additional constraints, for example, a specific substrate may lead to a particular nanoobject morphology. An impressive example of such a strategy is aryl halide C–C coupling on surfaces allowing for construction of various 1D and 2D structures. In particular, when aryl halide C–C coupling is combined with cyclodehydrogenation reaction it facilitates synthesis of miscellaneous graphene derivatives, such as nanoribbons of different widths and diverse edge topology.
关键词： On-Surface Polymerization,Semiconductor Surfaces,Aryl–Aryl Coupling,Ge(001):H Surface,Rutile Titania
更新于2025-09-10 09:29:36
-
Underpotential co-deposition of ternary Cu-Te-Se semiconductor nanofilm on both flexible and rigid substrates
摘要： To achieve homogeneous ternary compounds, the growth rates of the component species in a solution must be equal and the processes must be simultaneous. The conditions necessary for the growth of one species should not prevent the growth of the others. Herein we present a synthesis of Cu3Te2Se2 semiconductor nanofilms on indium tin oxide (ITO)-coated polyethylene terephthalate (ITO-PET), ITO-coated glass, and Au plate substrates by an electrochemical underpotential co-deposition (UPCD) method from the same solution at a constant potential. The chemical, morphological, and optical properties of the synthesized nanofilms were determined by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, ultraviolet-visible absorption spectroscopy (UV/Vis), and current-voltage (I-V) studies. The chemical formula of the deposited nanofilms was confirmed as Cu3Te2Se2 by X-ray photoelectron spectroscopy. The SEM images exhibited uniform nano-scale (~40 nm) distribution of the Cu3Te2Se2 nanofilms. The band gaps of the deposited films were determined according to the different deposition times and potentials. The XRD results showed crystalline and single-phase forms of Cu3Te2Se2 nanofilm. Finally, the I-V curves of the Cu3Te2Se2/ITO heterojunctions at room temperature (RT) under normal light conditions indicated matched those of a diode model.
关键词： Ternary Cu-Te-Se,Diode,Underpotential Co-deposition,Flexible surface,Electrochemistry,Semiconductor
更新于2025-09-10 09:29:36
-
Preparation of Indium Phosphide Substrates for Epilayer Growth
摘要： We have carried out an integrated study of technological steps in the preparation of indium phosphide substrates for the epitaxial growth of heterostructures. We have investigated the surface morphology and condition of indium phosphide in (100)-oriented substrates and tested various chemical etchants for final chemical surface processing. Our results demonstrate that an optimal substrate preparation process is two-step chemical–mechanical polishing on both sides using zeolite slurries, with chemical polishing in a mixture of bromine and isopropanol as the final step.
关键词： epitaxy,indium phosphide,semiconductor heterostructures,etching
更新于2025-09-10 09:29:36
-
Noise sources and their limitations on the performance of compound semiconductor hard radiation detectors
摘要： We report on the measurement of frequency dependent noise spectra of photoconductive ternary compounds Cs3Sb2I9, Rb3Sb2I9, Hg3Se2I2, and TlSn2I5 for hard radiation detectors. The major sources of noise in these detectors are attributed to pickup noise, white noise, and frequency related 1/f noise. At low frequencies, the noise spectral density function exhibited 1/f a behavior where α is less than or equal to one. For those samples with α equal to one, radiation detection performances of the detectors, in terms of spectral measurements, have been reported in previous publications. The origin of 1/f noise of those samples is attributed to carrier fluctuations associated with deep centers/trapped holes. For those samples with α less than one, the origin of the deviation from a linear 1/f dependence is unknown and currently under investigation. However, this deviation is correlated with higher background white noise and lowered detector performance, and thus indicates that the material needs to be further optimized. Noise measurements are a useful indicator for screening prospective materials and samples for detectors.
关键词： Electronics,radiation detector,noise,semiconductor
更新于2025-09-10 09:29:36
-
[IEEE 2018 International Power Electronics Conference (IPEC-Niigata 2018 –ECCE Asia) - Niigata, Japan (2018.5.20-2018.5.24)] 2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia) - Modeling and model parameter extraction of wide bandgap power semiconductor device, package, and circuit for simulating fast switching behavior
摘要： Wide band gap power semiconductor devices have superiority in fast switching operation, when compared to Si IGBT and PiN diodes for voltage range from several hundred to several kilo volts. The fast switching operation gives high di/dt and dv/dt, which results in inducing surge voltage and EMI noise for poorly designed circuit. The precise dynamical model of power device and peripheral component is necessary in estimating these transient phenomenon. This paper presents the dynamical model of wide bandgap power semiconductor devices, package of power device, and circuit wiring. The fixture configurations to extract model parameter is also presented. The static blocking and conducting condition for power device is characterized with curve tracer. The terminal capacitance of power device dominates switching dynamic terminal characteristics. Then, voltage dependency of capacitances are characterized with the developed fixture, which can cope with normally on transistor characterization. The electro magnetic analysis of package and circuit to identify parasitic component is also addressed in the paper. The switching behaviors of power device and the phenomenon in the circuit are discussed based on the model and extracted model parameters.
关键词： parameter extraction,wide bandgap power semiconductor devices,modeling,fast switching behavior,simulation
更新于2025-09-10 09:29:36
-
Elasto-electric coupling for direct electric field distribution measurement in semiconductor structures
摘要： Semiconductor materials are widely used in electronic industry, but their electrical characterization remains complex to estimate without a good model. It has already been shown that an elasto-electric coupling can be used to directly and non-destructively probe the electrical properties at the external interfaces of semi-conductor structures. In this paper, it is shown that such a coupling can also be used to probe the inner interfaces of semi-conductor structures. This capability is demonstrated by using a specific semi-conductor structure including a buried silicon p-n junction 720 lm away from the external electrodes. The signal generated by the elasto-electric coupling clearly shows separately the electric field at the electrodes and at the buried junction. The contact potential at the buried junction estimated from the measurements is in accordance with the semiconductor doping. This makes it possible to use an elasto-electric coupling for the complete characterization of semiconductor structures.
关键词： Pressure-Wave-Propagation method,elasto-electric coupling,semiconductor structures,p-n junction,electric field distribution
更新于2025-09-10 09:29:36
-
Metal-free Semiconductor Photocatalysis for sp2 C-H Functionalization with Molecular Oxygen
摘要： Designing metal-free catalysts for solar energy conversion is a long-standing challenge in semiconductor photoredox catalysis (SPC). With visible-light-responsive hexagonal boron carbon nitride (h-BCN) as a non-metal photocatalyst, this system affords C–H/N–H coupling products with broad substitution tolerance and high efficiency with molecular oxygen as the terminal oxidant. The catalyst exhibits remarkable performance for the selective C-H functionalization of electron-rich arenes to C-N products (yields up to 95%) and good stability (6 recycles). Both nitrogen heteroarenes and amine salts are competent coupling nucleophiles. Mechanically, the reactive oxygen species are superoxide anion radical (O2??) and H2O2, which are proved by electron spin resonance (ESR) data, KI-starch, and control experiments. In addition, kinetic isotope effect (KIE) experiments indicate that C–H bond cleavage is not involved in the rate limiting step. This semiconductor-based photoredox system allows for C–H amination free of any metals, ligands, strong oxidants, and additives. It provides a complementary avenue to C–H functionalizations and enables synthetic applications efficiently in a sustainable manner.
关键词： Radical,Semiconductor Photoredox Catalysis,Heterogeneous Catalysis,Visible Light,C-H Fuctionalizaition
更新于2025-09-10 09:29:36