Diffusivity-mobility ratio in heavily doped quantum wells under intense light waves

In this paper we investigate the influence of strong light waves on the two dimensional diffusivity mobility ratio in heavily doped quantum wells of III–V, ternary and quaternary semiconductors within the framework of k.p formalism by formulating a new electron energy spectrum. It appears taking heavily doped quantum wells of InSb, InAs, Hg1–x Cd x Te and In1–x Ga x As1–y P y lattice matched to InP as examples that the said ratio decreases with increasing film thickness, intensity, wave length and increases with increasing surface electron concentration exhibiting spikey oscillations because of the crossing over of the Fermi level by the quantized level in quantum wells and the quantized oscillation occurs when the Fermi energy touches the sub-band energy. The ratio increases with decreasing alloy composition where the variations are totally band structure dependent. Under certain limiting conditions all the results for all the cases get simplified into the well-known parabolic energy bands and thus confirming the compatibility test. We have suggested an experimental method of determining heavily doped two dimensional diffusivity mobility ratios for materials having arbitrary dispersion laws

On the field emission from quantum wires of non-parabolic semiconductors: Simplified theory and relative assessment

An attempt is made to present a simplified theoretical formulation of the Fowler-Nordheim field emission (FNFE) in quantum wires (Qws) of non-linear optical materials on the basis of a newly formulated electron dispersion law by considering various types of anisotropies of the energy band constants within the framework of k.p formalism. We also study FNFE from Qws of III–V, II–VI and Bismuth by using the appropriate band models. Taking Qws of CdGeAs2, InAs, InSb, GaAs, Hg1−x Cd x Te and In1−x Ga x AsP1−y lattice matched to InP, CdS and Bi as examples, we observe that, the FNFE increases with increasing film thickness due to the existence van- Hove singularity and the magnitude of the quantum jumps are not of same height indicating the signature of the band structure of the material concerned. The appearance of the humps of the respective curves is due to the redistribution of the electrons among the quantized energy levels when the quantum numbers corresponding to the highest occupied level changes from one fixed value to the others. Although the field current varies in various manners with all the variables in all the cases as evident from all the curves, the rates of variations are totally band-structure dependent. All the results as derived in this paper get transformed in to the well known Fowler-Nordheim formula under certain limiting conditions, and thus confirming the compatibility test

Seebeck coefficient in quantum dots and quantum dot super lattices of heavily doped semiconductors under large magnetic field

In this chapter, an attempt is made to study the Seebeck coefficient under large magnetic field (S) in quantum dots of heavily doped nonlinear optical, III-V, II-VI, GaP, Ge, Te, PtSb2, II-V, GaSb, stressed materials, IV-VI, Lead Germanium Telluride, Zinc and Cadmium diphosphides and Bi2Te3 on the basis of newly formulated carrier dispersion laws respectively. We have also investigated the S in heavily doped III-V,IIVI, IV-VI, HgTe/CdTe and strained layer Quantum Dot Superlattices (QDSL) with graded interfaces together with the effective mass superlattices of the afore mentioned materials by formulating new carrier energy spectra. It has been found that the S for the said heavily doped quantum dots and QDSL oscillate with increasing thickness and changes with increasing electron concentration in various manners for all types of superlattices with two entirely different signatures of quantization as appropriate in respective cases of the aforementioned quantized structures. © 2013 by Nova Science Publishers, Inc. All rights reserved