Current-voltage Characteristics Of Si Research Articles

Simulation and Comparison of Current Voltage Characteristics of Si and Ge based Bio Field Effect Transistor by Varying Oxide Thickness to Get Better Sensitivity

Aim: The current voltage characteristics of Silicon based BIOFET and Germanium based BIOFET are simulated by varying their oxide thickness ranging from 1nm to 100nm. Materials and Methods: The electrical conductance of Silicon based BIOFET (n=320) was compared with Germanium based BIOFET (n=320) by varying oxide thickness ranging from 1nm to 100nm in the NanoHub© tool simulation environment. Results: Germanium based BIOFET has significantly higher conductance than Silicon based BIOFET. The optimal gate oxide thickness for maximum conductivity was 1nm for Silicon based BIOFET and 35nm for Germanium based BIOFET. Conclusion: Within the limits of the study, Germanium based BIOFET with oxide thickness of 35nm offers the best conductivity.

Si Esaki diodes with high peak to valley current ratios

We report room temperature current voltage characteristics of Si p+-i-n+ Esaki diodes integrated on silicon substrates. The diodes were fabricated by low-temperature molecular beam epitaxy. Very high and abrupt p- and n-type dopant transitions into the 1020 cm−3 ranges are achieved by boron and antimony, respectively. The integrated devices are realized without a postgrowth annealing step. The silicon Esaki diodes show negative differential resistance at room temperature with excellent peak to valley current ratios up to 3.94. A variation in the thickness of the silicon tunneling barrier changes the peak current density over three orders of magnitude.

(IV2)1−x (III-V)x solid solutions obtained from a bounded tin melt-solution

The formation of a continuous series of substitutional solid solutions is theoretically considered from the viewpoint of taking into account generalized moments and differences in the valence and the covalent radii of atoms or molecules of initial components. These considerations are used to develop technology for the fabrication of (Si2)1−x(GaAs)x (0≤x≤0.96) and (Si2)1−x(GaP)x (0≤x≤1) epitaxial layers on silicon substrates from a tin melt-solution by the forced cooling method. The distribution of components over the thickness of the (Si2)1−x(GaAs)x and (Si2)1−x(GaP)x layers, the photosensitivity, and the current-voltage characteristics of Si-(Si2)1−x(GaAs)x and Si-(Si2)1−x(GaP)x heterostructures were studied. The analysis of results of X-ray investigations and photoelectric properties indicate that the grown epitaxial layers of (IV2)1−x(III-V)x solid solutions are structurally perfect.

Photoelectric characteristics of infrared photodetectors with blocked hopping conduction

It is shown that the current-voltage characteristics of Si:As-based structures that have blocked hopping conduction (blocked-impurity-band, or BIB, structures) and are subjected to infrared radiation in the photosensitivity range have two distinct portions. In the first portion, the photocurrent is controlled by an infrared-radiation flux and by an avalanche impurity-related breakdown. In the second portion, the photocurrent is controlled by merging of the depletion region with the contact N++ region. It is shown that the avalanche-multiplication mode can be used in focal multielement photodetector systems. The uniformity of photoelectric parameters over an array of elements in a system of focal multielement photodetectors operating in the avalanche-multiplication mode compares well with that observed in BIB arrays operating without avalanche multiplication.

Current-voltage characteristics of Si:As blocked impurity band photodetectors with hopping conductivity (BIB-II)

The current-voltage characteristics of Si:As blocked impurity band (BIB) structures are investigated. The behavior of the dark current in the temperature range 4.2–25 K and in the range of bias voltages −3 to +3 V is analyzed. It is shown that the main features of the I-V characteristics are governed by the thermal-field injection of charge carriers from the contacts to the BIB structure. The details of the I-V characteristics for bias voltages of both polarities are attributed to generation-recombination processes between the conduction band and the impurity band of the N+ photoconductive layer. It is established that the blocking layer can accumulate charge of both signs, influencing the formation of the dark I-V characteristics.

Current-voltage characteristics of Si:As-based photodetectors with blocked hopping conductivity

The results of an experimental investigation of the current-voltage characteristics of Si:As-based structures with blocked hopping conductivity are reported. The behavior of the dark current in the temperature range T=7–25 K with bias voltages from −4 to +4 V is analyzed and views about the mechanisms of dark-current flow are presented. Recommendations are developed for choosing the bias voltage on the structures for optimal operation as an IR photodetector.

Current-voltage characteristics of Si:B blocked impurity-band structures under conditions of hopping-transport-limited photoresponse

The photoconductivity of Si:B blocked-impurity-band (BIB) structures with boron concentration in the active layer ∼1018 cm−3 has been studied. Measurements were performed in the temperature range 4.2–10 K at different intensities of the exciting radiation 1010–1015 photons/cm2·s. Photoexcitation at 5.5 µm was realized using a semiconductor laser. At temperatures below 6 K and low bias voltages (<0.5 V) the current-voltage characteristics were found to have a threshold-like character. The threshold voltage rises as the temperature is lowered and the radiation intensity is increased. A model based on the Frenkel’-Poole effect in the impurity band has been developed. This model can be used to numerically describe the current-voltage characteristics with accuracy better than 5%. As a result, it is found that the photoconductivity rises and then reaches a plateau as the radiation intensity increases. Under these conditions, as under equilibrium conditions (in darkness), the hopping conductivity also depends exponentially on the electric field. This fact is explained in terms of the destruction by the electric field of (A+-A−) impurity complexes which appear under nonequilibrium conditions.

Current-Voltage Characteristics of Si p-i-n Negative Resistance Diodes Doped with Gold

Current-Voltage Characteristics of Si p-i-n Negative Resistance Diodes Doped with Gold

Double injection in Si:In devices

The current-voltage characteristics of Si:In double-injection devices were measured up to breakdown in the temperature range 20–80 K. To vary the amount of optical carrier generation the devices were either exposed to a 50 K cold shield or a 300 K background. The breakdown voltages were found to be strongly dependent on device temperature and irradiation intensity. By using simple analytical expressions it is shown that the unexpected low values at high temperatures or at high irradiation levels are due to large densities of thermally or optically generated holes. To obtain a satisfactory agreement between theory and experiment the regional approximation method is employed. The analysis extends previous treatments by taking into account field-dependent mobilities and capture coefficients. The description of the prebreakdown characteristics includes also the lowering of the ionization energies of the acceptor centers at high field strengths.

Uniaxial stress effects on double injection diodes

Uniaxial stress effects on the current-voltage characteristics of Si and Ge double injection diodes are described and discussed. The threshold and the minimum voltages were decreased and the current flowing in the diode was increased with stress. These variations can qualitatively be explained by the change of mobility of the carrier and the capture cross section, and by the stress-induced deep levels.