Numerical Analysis of Current–Voltage Characteristics of LWIR nBn and p-on-n HgCdTe Photodetectors

We performed numerical analysis of the current–voltage characteristics of long-wavelength infrared unipolar HgCdTe nBn photodetectors and compared those results with those of conventional p-on-n HgCdTe photodiodes. A computer program was applied to explain in detail the impact of the charge carrier generation and recombination processes on current densities. In our model the carrier diffusion, thermal generation–recombination, band-to-band tunneling, trap-assisted tunneling (via states located at mercury vacancies as well as dislocation cores), and impact ionization are included as potential limiting mechanisms. To validate the model, we compared the theoretical predictions with experimental data of high-quality p-on-n photodiodes published in the literature.     

Analysis of Current–Voltage Characteristics in UV AlGaN Heterostructure FPAs

Journal of Communications Technology and Electronics - UV visible-blind and solar-blind 320 × 256 photodiode arrays based on AlxGa1 – xN heteroepitaxial structures (AlGaN HES) and...     

Analysis of the Effect of Spacer Layers on Nonlinear Distortions of the Current–Voltage Characteristics of GaAlAs/InGaAs pHEMTs

Semiconductors - The paper presents the results of modeling the electrophysical parameters of AlGaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor (pHEMT) structures via...     

Current–Voltage Characteristics of Two-Electrode Elements with Carbon Nanotubes

Planar two-electrode nonlinear elements using carbon nanotubes doped with platinum metals are created and investigated. Among the nanotubes, branched ones are found. If doped, these nanotubes take a regular form. With appropriate doping, limiting currents above 1 A are achieved. However, the problem of contact between carbon nanotubes and electrodes has yet to be solved.     

The Effect of Ballistic Conduction Electrons on the Current–Voltage Characteristics of Thin-Film Bismuth-Based Cross-Shaped Microstructures

A decrease in the residual pressure to 10^–6 Pa during the deposition of bismuth films results in low-temperature metallic conductance of the films. Cross-shaped microstructures made of these films exhibit the property of ballistic transport, which is typical of two-dimensional systems. This property shows up as a bend of the current–voltage characteristics (CVCs). The value of bend resistance changes in inverse proportion to the width of interconnects and drops with increasing temperature in the range of 4.2–77 K. The free path of conduction electrons, are responsible for the CVC bend, was estimated at more than 1 m.     

Effect of Uniaxial Elastic Deformation on the Current–Voltage Characteristic of Surface-Barrier Sb–p-Si〈Mn〉–Au Diodes

Semiconductors - The effect of uniaxial elastic deformation on the current–voltage characteristic of surface–barrier Sb–p-Si〈Mn〉–Au diodes is studied. It is...     

Impurity Deionization Effects on Surface Recombination DC Current–Voltage Characteristics in MOS Transistors

Impurity deionization on the direct-current current–voltage characteristics from electron–hole recombination (R-DCIV) at SiO₂/Si interface traps in MOS transistors is analyzed using the steady-state Shockley-Read-Hall recombination kinetics and the Fermi distributions for electrons and holes. Insignificant distortion is observed over 90% of the bell-shaped R-DCIV curves centered at their peaks when impurity deionization is excluded in the theory. This is due to negligible impurity deionization because of the much lower electron and hole concentrations at the interface than the impurity concentration in the 90% range.     

High Voltage Breaker Current Monitoring and FaultDiagnosis System Based on Fiber Current Sensor

Abstract: The current measuring principle, the hardware structure and the software functions of a high voltage breaker current monitoring and fault diagnosis system are introduced. A simple algorithm for calculating the current effective value is given. The cut - off characteristics of the breaker are classified. This system can provide a foundation for reasonably determining the breaker service period.     

Photosensitive Elements Based on Two-Dimensional Bismuth Telluride: Obtaining and Current–Voltage Characteristics

Journal of Communications Technology and Electronics - Bismuth telluride based photosensitive elements were obtained and their properties were studied. Liquid exfoliation was used for bismuth...     

Impact of the Percolation Effect on the Temperature Dependences of the Capacitance–Voltage Characteristics of Heterostructures Based on Composite Layers of Silicon and Gold Nanoparticles

Semiconductors - The temperature dependences of the capacitance–voltage characteristics and deep-level spectra of a Au–n-Si:Au–Si–p-Si heterostructure based on a composite...     

Dislocation Reduction by Glide in Epitaxial IV–VI Layers on Si Substrates

It is explained with a simple model why the reduction of threading dislocation (TD) densities in epitaxial lattice and thermal expansion mismatched IV?CVI layers such as PbSe(111) on Si(111) substrates follows a 1/h ² dependence where h is the thickness of the layer. This is in contrast to the 1/h dependence for III?CV and II?CVI layers grown on mismatched substrates. The 1/h ² dependence results since the thermal mismatch strain is mainly reduced by glide and reactions of the TD in their main {100}-type glide system of the NaCl-type IV?CVI semiconductors. In addition, multiple thermal cycles lead to further reduction of the TD densities by glide and fusion since fusion does not cause dislocation blocking.     

Technology for Producing Schottky Contacts Based on an IrSi–Si Composite

Russian Microelectronics - In this study, in order to obtain Schottky contacts based on an IrSi–Si composite, n- and p-type silicon wafers doped, respectively, with boron and phosphorus with...     

Analysis of the Temperature Dependence of the Capacitance–Voltage and Conductance–Voltage Characteristics of Au/TiO2(rutile)/n-Si Structures

The capacitance–voltage–temperature (C–V–T) and the conductance/angular frequency–voltage–temperature (G/ω–V–T) characteristics of Au/TiO₂(rutile)/n-Si Schottky barrier diodes (SBDs) were investigated over the temperature range from 200 K to 380 K by considering the series resistance effect. Titanium dioxide (TiO₂) was deposited on n-type silicon (Si) substrate using a direct-current (DC) magnetron sputtering system at 200°C. To improve the crystal quality, the deposited film was annealed at 900°C to promote a phase transition from the amorphous to rutile phase. The C ^?2 versus V plots gave a straight line in the reverse-bias region. The main electrical parameters, such as the doping concentration (N _D), Fermi energy level (E _F), depletion layer width (W _D), barrier height (ф _CV), and series resistance (R _S), of Au/TiO₂(rutile)/n-Si SBDs were calculated from the C–V–T and the G/ω–V–T characteristics. The obtained results show that ф _CV, R _S, and W _D values decrease, while E _F and N _D values increase, with increasing temperature.     

Effect of Annealing on the Surface Morphology and Current–Voltage Characterization of a CZO Structure Prepared by RF Magnetron Sputtering

Semiconductors - In this study, we investigated the Cu-doped ZnO (CZO) structure. This structure was deposited on the Si and glass substrates using the RF magnetron sputtering technique....     

A Novel Local-Dielectric-Thickening Technique for Performance Improvements of Spiral Inductors on Si Substrates

A novel local-dielectric-thickening technique is presented for performance improvements of Si-based spiral inductors.This technique employs the processes of deposition,photolithography,and wet-etching,to locally thicken the oxide layer under the inductor,which can decrease the substrate loss and improve the inductor performance.Both the structures and processes are compact,economical,and compatible with CMOS processing.Several square spiral inductors with different inductances are fabricated,and the quality factors and the self-resonant frequencies both increase clearly with this proposed technique:for the 10,5，and 2nH inductors,the peak quality factors are effectively improved by 46.7%,49.7%，and 686%,respectively;however,the improvement percents of the selfresonant frequencies are more significant,which are 92.1%,91.0%,and no less than 68.1%，respectively.     

Study of the Current–Voltage Characteristics of InAsSb-Based LED Heterostructures in the 4.2–300 K Temperature Range

Semiconductors - The results of a study in the temperature range 4.2–300 K of the current–voltage characteristics of light emitting diode (LED) heterostructures with an active region...     

Analysis on Conductivity of nc—Si：H Films

A conduction channel model is propsed to explain the high conductivity property of nc-Si:H.Detailed energy band diagram is developed based on the analysis and calculation ,and the conductivity of the nc-Si:H was then analysed on the basis of energy band theory.It is assumed that the conductivity of the nc-Si:H stems from two parts:the conductance of the interface,where the transport mechanism is identified as a thermal -assisted tunneling process,and the conductance along the channel around the grain,which mainly determined the high conductivity of the nc-Si:H.The conductivity of nc-Si:H is calculated and compared with the experiment data .The theory is in agreement with the experiment.     

Model Development for Current–Voltage and Transconductance Characteristics of Normally-off AlN/GaN MOSHEMT

In this paper, an AlN/GaN-based MOSHEMT is proposed, in accordance to this, a charge control model has been developed analytically and simulated with MATLAB to predict the characteristics of threshold voltage, drain currents and transconductance. The physics based models for 2DEG density, threshold voltage and quantum capacitance in the channel has been put forward. By using these developed models, the drain current for both linear and saturation models is derived. The predicted threshold voltage with the variation of barrier thickness has been plotted. A positive threshold voltage can be obtained by decreasing the barrier thickness which builds up the foundation for enhancement mode MOSHEMT devices. The predicted I_d–V_gs, I_d–V_ds and transconductance characteristics show an excellent agreement with the experimental results and hence validate the model.     

Shockley–Haynes Characterization of Minority-Carrier Drift Velocity,Diffusion Coefficient,and Lifetime in HgCdTe Avalanche Photodiodes

A combined study of the avalanche gain characteristics of HgCdTe electron-avalanche photodiodes (e-APDs) and of the minority electron properties in the p-type absorber using Shockley–Haynes (SH) measurements is presented for various Cd compositions x _Cd. Ideal gain performance associated with a low excess noise factor F = 1.2 have been measured at T = 80 K down to cutoff wavelengths of λ _c = 2.9 μm. The observation of both a record high, exponentially increasing gain of M = 600 in short-wave e-APDs and a low excess noise factor proved that the exclusive electron multiplication is stable down to x _Cd = 0.4. Zero-flux measurements at 80 K confirmed that the dark current tends to decrease at constant gain as x _Cd increases. Measurements using a readout integrated circuit allowed us to establish a new record in sensitivity for APDs: I _{eq_in} = 2 aA, corresponding to 12 e/s at gain of M = 24 in an e-APD with λ _c = 2.9 μm. SH measurements enabled direct estimation of the electron diffusion coefficient, drift velocity, and lifetime in the p-type absorber of the e-APDs as a function of electric field at temperatures between 80 K and 200 K. Measurements at 80 K yielded lifetimes consistent with the values expected for the nominal doping of the samples. The low-field electron drift mobility, estimated from the drift velocity, was found to be a factor of 0.4 to 0.5 lower than the mobility in n-type material with the same composition. In mid-wave (MW) infrared samples with λ _c = 5.3 μm, the mobility was observed to be μ _ep = 15 kcm²/Vs to 20 kcm²/Vs, being less than μ _en ≈ 40 kcm²/Vs to 50 kcm²/Vs. The reduction in mobility can, in part, be attributed to scattering by ionized acceptors and heavy holes. The diffusion mobility, estimated from the diffusion coefficient, was systematically higher than the drift mobility, indicating diffusion of hot electrons with a temperature higher than that of the lattice. The saturation velocity, v _{sat_ep} = 2 × 10⁶ cm/s to 6 × 10⁶ cm/s, did not correlate with the Cd composition in the samples. The measured saturation velocities made it possible to estimate the timing jitter in p-type absorbers with a built-in electric field. Jitter below 100 ps was estimated for SW and MW APDs with absorbing layer thicknesses up to 4 μm.