An attempt is made to derive an expression for the effective electron mass along the direction of a magnetic field in bismuth under magnetic quantization by using the generalized dispersion relation of the conduction electrons as proposed by Meclure and Choi. It is found that the oscillatory quantum number dependent behaviour of the effective electron mass at the Fermi level in bismuth is solely due to band non-parabolicity and is a characteristic feature of the above model. © 1986, Verlag der Zeitschrift fur Naturforschung. All rights reserved.

K P GHATAK

M MONDAL

Fulltext

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

&nbsp;

The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

&nbsp;

It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Zeitschrift fur Naturforschung - Section A Journal of Physical Sciences

In this paper we study the effective electron mass (EEM) in Nano wires (NWs) of nonlinear optical materials on the basis of newly formulated electron dispersion relation by considering all types of anisotropies of the energy band constants within the framework of k . p formalism. The results for NWs of III-V, ternary and quaternary semiconductors form special cases of our generalized analysis. We have also investigated the EEM in NWs of Bi, IV-VI, stressed Kane type materials, Ge, GaSb and Bi2Te3 by formulating the appropriate 1D dispersion law in each case by considering the influence of energy band constants in the respective cases. It has been found that the 1D EEM in nonlinear optical materials depend on the size quantum numbers and Fermi energy due to the anisotropic spin orbit splitting constant and the crystal field splitting respectively. The 1D EEM is Bi, IV-VI, stressed Kane type semiconductors and Ge also depends on both the Fermi energy and the size quantum numbers which are the characteristic features of such NWs. The EEM increases with increase in concentration and decreasing film thickness and for ternary and quaternary compounds the EEM increases with increase in alloy composition. Under certain special conditions all the results for all the materials get simplified into the well known parabolic energy bands and thus confirming the compatibility test.

Journal of Computational and Theoretical Nanoscience

Simple theoretical analysis of the effective electron mass in semiconductor nanowires

In this paper, an attempt is made to study the effective electron mass (EEM) in Quantum wires (QWs) of III-V, ternary and quaternary materials on the basis of three and two band models of Kane within the framework of kp formalism. It has been found, taking QWs of InAs, InSb, GaAs, Hg1-xCdxTe and In1-xGaxAs1-yPy that the 1D EEM increases with electron concentration per unit length and decreases with increasing film thickness respectively. For ternary and quaternary materials the EEM increases with increase in alloy composition. Under certain special conditions all the results for all the 1-D materials get simplified into the well known parabolic energy bands and thus confirming the compatibility test. The results of this paper find two applications in the fields of nanoscience and technology. Copyright © 2012 American Scientific Publishers All rights reserved.

Journal of Nanoscience and Nanotechnology

Effective electron mass in quantum wires of III-V, ternary and quaternary materials

We study theoretically the thermoelectric power in the presence of a large magnetic field (TPM) in heavily doped III-V, II-VI, PbTe/PbSnTe, strained layer and HgTe/CdTe quantum dot superlattices (QDSLs) with graded structures on the basis of newly formulated electron energy spectra and compare the same with that of the constituent materials. It has been found, taking heavily doped GaAs/Ga1-xAlxAs, CdS/CdTe, PbTe/PbSnTe, InAs/GaSb and HgTe/CdTe QDSLs as examples, that the TPM increases with increasing inverse electron concentration and film thickness, respectively, in different oscillatory manners and the nature of oscillations is totally band structure dependent. We have also suggested the experimental methods of determining the Einstein relation for the diffusivity-mobility ratio, the Debye screening length and the electronic contribution to the elastic constants for materials having arbitrary dispersion laws. © 2006 Elsevier B.V. All rights reserved.

Physica E: Low-Dimensional Systems and Nanostructures

Simple theoretical analysis of the thermoelectric power in quantum dot superlattices of non-parabolic heavily doped semiconductors with graded interfaces under strong magnetic field

The Einstein relation is studied for the diffusivity-mobility ratio of the carriers in ultrathin films of bismuth in the presence of crossed electric and magnetic fields at very low temperatures, and the numerical results are presented for McClure and Choi, hybrid, Cohen, Lax, and ellipsoidal parabolic energy bands by formulating the respective modified carrier energy spectra. It is found that this ratio increases with decreasing film thickness, increasing electron concentration, and decreasing magnetic field. The quantum oscillations of the ratio show up much more significantly in the McClure than in the other models. © 1988 Plenum Publishing Corporation.

Journal	Zeitschrift fur Naturforschung - Section A Journal of Physical Sciences
Publisher	VERLAG Z NATURFORSCH
ISSN	0932-0784
Open Access	No