Semiconductor Barrier Structures Research Articles

Deep levels model identification in semiconductor barrier structures

Semiconductor barrier structures are essential elements of modern integrated electronics. The band theory explains properties of barrier structures using deep levels in the semiconductor band gap. The relentless interest in studying the characteristics of deep levels is due to practical needs, ambiguous interpretations and scatters of experimental results obtained by different researchers. In order to increase the accuracy of the measurements, a modified capacitive deep-level transient spectroscopy technic of has been developed. A mathematical model of the hardware transformations of the barrier structure capacitance transient signal is developed and provided in this article. The model considers the nonexponentiality of the capacitance transient and the spectrometer hardware transformations nonlinearity. There are the results of the deep levels experimental studies in silicon diodes and the model parametric identification. The technic makes it possible to reduce by five or more times the six-sigma confidence interval for the discrete deep level activation energy determining in comparison with the round robin test results of ASTM F978-02.

Effect of Rashba spin–orbit coupling on the spin polarized transport in diluted magnetic semiconductor barrier structures

We investigate theoretically the effects of Rashba spin–orbit coupling on the spin dependent transport through diluted magnetic semiconductor single and double barrier structures in the presence of a magnetic field. We find that the Rashba spin–orbit coupling gives rise to an enhancement of the negative tunnelling magnetoresistance of the diluted magnetic semiconductor single barrier structure and a pronounced beating pattern in the tunnelling magnetoresistance and spin polarization of the diluted magnetic semiconductor double barrier structure.

SOFTWARE FOR INVETIGATION OF CURRENT TRANSPORT PROCESSES IN SEMICONDUCTOR STRUCTURES

The paper reports the development of the software “Solar Cell Simulator”, designed for numerical modeling of current transport phenomena in the different semiconductor barrier structures depending on the type and magnitude of external and internal parameters (such as intensity and spectrum of illumination, applied voltage, type and parameters of semiconductor materials, impurity concentration, etc.).

Resonant thermal transport in semiconductor barrier structures

I report that thermal single-barrier (TSB) and thermal double-barrier (TDB) structures (formed, for example, by inserting one or two regions of a few Ge monolayers in Si) provide both a suppression of the phonon transport as well as a resonant-thermal-transport effect. I show that high-frequency phonons can experience a traditional double-barrier resonant tunneling in the TDB structures while the formation of Fabry-Perot resonances (at lower frequencies) causes quantum oscillations in the temperature variation of both the TSB and TDB thermal conductances ${\ensuremath{\sigma}}_{\mathrm{TSB}}$ and ${\ensuremath{\sigma}}_{\mathrm{TDB}}.$

Oscillating magnetoresistance in diluted magnetic semiconductor barrier structures

Ballistic spin polarized transport through diluted magnetic semiconductor single and double barrier structures is investigated theoretically using a two-component model. The tunneling magnetoresistance (TMR) of the system exhibits oscillating behavior when the magnetic field is varied. An interesting beat pattern in the TMR and spin polarization is found for different nonmagnetic semiconductor/diluted magnetic semiconductor double barrier structures which arises from an interplay between the spin-up and spin-down electron channels which are split by the $s\ensuremath{-}d$ exchange interaction.

Skin effect and response of semiconductor barrier structures

The problem of the skin effect in a finite-width barrier structure of the type conductor (metal or semiconductor) — barrier (specifically, tunneling) — conductor is solved. It is shown that the excitation of special “barrier” plasma polaritons (BPPs), which are localized in the barrier and the near-barrier region and possess a 2D spectrum, is possible in this regime. An analytical relation between the BPP spectrum and the linear dynamical impedance of the structure as well as its rectifying characteristics is found. The excitation of BPPs greatly increases the nonlinear response of the structure. It is shown that the linear and nonlinear response of the typical semiconductor tunneling structures in the THz frequency range is determined by the excitation of BPPs.

Local activation energy and shape factor of current-voltage curve as investigation tools for semiconductor barrier structures

Modeling of the I(V,T) dependence in thin film semiconductor structures suggests that experimental data, on temperature and voltage dependent activation energy and shape factor of the current, give significant information on the recombination process within the structure. Grounds are thus laid for further investigation on quantum well effects within such structures.