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Journal ArticleDOI

A simple theoretical analysis of the thermo-electric power in quantum dots of nonparabolic semiconductors in the presence of a parallel magnetic field

01 Sep 1995-Nanostructured Materials (Pergamon)-Vol. 5, Iss: 43654, pp 769-776
Abstract: In this paper an attempt is made to study the thermoelectric power in quantum dots of non-parabolic semiconductors in the presence of a parallel magnetic field on the basis of a new electron dispersion law. It is found, taking Hg1 − xCdxTe and In 1 − xGaxAsyP1 − y lattice matched to InP as examples, that the thermoelectric power exhibits strong oscillatory dependencies with increasing magnetic field, alloy composition and thickness of the quantum dots, respectively. The thermopower increases with decreasing electron concentration and the numerical values of the same power in quaternary materials are greater in comparison with ternary compounds.
Topics: Quantum dot (58%), Seebeck coefficient (55%), Magnetic field (55%), Electron (52%), Semiconductor (51%)
Citations
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Journal ArticleDOI
Abstract: We present a simplified theoretical formulation of the thermoelectric power (TP) under magnetic quantization in quantum wells (QWs) of nonlinear optical materials on the basis of a newly formulated magneto-dispersion law. We consider the anisotropies in the effective electron masses and the spin-orbit constants within the framework of k.p formalism by incorporating the influence of the crystal field splitting. The corresponding results for III-V materials form a special case of our generalized analysis under certain limiting conditions. The TP in QWs of Bismuth, II-VI, IV-VI and stressed materials has been studied by formulating appropriate electron magneto-dispersion laws. We also address the fact that the TP exhibits composite oscillations with a varying quantizing magnetic field in QWs of n-Cd3As2, n-CdGeAs2, n-InSb, p-CdS, stressed InSb, PbTe and Bismuth. This reflects the combined signatures of magnetic and spatial quantizations of the carriers in such structures. The TP also decreases with increasing electron statistics and under the condition of non-degeneracy, all the results as derived in this paper get transformed into the well-known classical equation of TP and thus confirming the compatibility test. We have also suggested an experimental method of determining the elastic constants in such systems with arbitrary carrier energy spectra from the known value of the TP. (C) 2010 Elsevier Ltd. All rights reserved.

6 citations


Book ChapterDOI
01 Jan 2012-
Abstract: In this book, we have discussed many aspects of TPSM based on the dispersion relations of the nanostructures of different technologically important materials having different band structures in the presence of 1D, 2D, and 3D confinements of the wave-vector space of the charge carriers, respectively. In this chapter, we discuss few applications in this context in Sect. 14.2 and we shall also present a very brief review of the experimental investigations in Sect. 14.3 which is a sea in itself. Section 14.4 contains the single experimental open research problem.

4 citations


Book ChapterDOI
01 Jan 2015-
TL;DR: The concept of band gap measurement in the presence of intense external light waves is discussed and additional five related applications in this context are presented.
Abstract: The concept of band gap measurement in the presence of intense external light waves is also discussed and we present additional five related applications in this context. Besides, the experimental aspects of the EP from quantized structures have also been discussed very briefly. This chapter contains a single multi-dimensional deep open research problem.

1 citations


Book ChapterDOI
01 Jan 2010-
Abstract: In recent years, with the advent of Quantum Hall Effect (QHE) [1,2], there has been considerable interest in studying the thermoelectric power under strong magnetic field (TPSM) in various types of nanostructured materials having quantum confinement of their charge carriers in one, two, and three dimensions of the respective wave-vector space leading to different carrier energy spectra [3–38]. The classical TPSM equation as mentioned in the preface is valid only under the condition of carrier nondegeneracy, is being independent of carrier concentration, and reflects the fact that the signature of the band structure of any material is totally absent in the same.

1 citations


Book ChapterDOI
01 Jan 2016-
Abstract: In this chapter the DR in Quantum Wells of HD III–V semiconductors in the presence of magnetic field have been formulated in Sect. 1.2.1. On the basis of these fundamental equations, the DR in Nano Wires of HD III–V semiconductors in the presence of magnetic field has been investigated in Sect. 1.2.2. The Sect. 1.2.3 explores the DR in Quantum Dot of HD III–V semiconductors in the presence of magnetic field. The DR in Quantum Wells of HD III–V semiconductors in the presence of cross fields has been investigated in Sect. 1.2.4. The DR in Nano-Wires of HD III–V semiconductors in the presence of cross fields has been studied in Sect. 1.2.5. The DR in Quantum Dot of HD III–V semiconductors in the presence of cross fields has been investigated in Sect. 1.2.6. The DR in Quantum Wells of HD IV–VI semiconductors in the presence of magnetic field has been studied in Sect. 1.2.7. The DR in Nano Wires of HD IV–VI semiconductors in the presence of magnetic field has been investigated in Sect. 1.2.8. The DR in Quantum Dot of HD IV–VI semiconductors in the presence of magnetic field has been studied in Sect. 1.2.9. The DR in cylindrical Quantum Dot of III–V semiconductors in the presence of crossed electric and magnetic fields has been investigated in Sect. 1.2.10. The DR in Quantum Wells of HD III–V Semiconductors in the presence of arbitrarily oriented magnetic field has been studied in Sect. 1.2.11. The Sect. 1.4 contains 16 open research problems, which form the integral part of this chapter.

1 citations


References
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Journal ArticleDOI
Abstract: tory since one may come to the conclusion that such a complicated system like a semiconuctor is not useful for very fundamental discoveries. Indeed, most of the experimental data in solid state physics are analyzed on the basis of simplified theories, and very often the properties of a semiconductor device is described by empirical formulas since the microscopic details are too complicated. Up to 1980 nobody expected that there exists an effect like the Quantized Hall Effect, which depends exclusively on fundamental constants and is not affected by irregularitie s in the semiconductor like impurities or interface effects. The discovery of the Quantized Hall Effect (QHE) was the result of systematic measurements on silicon field effect transistors-the most important device in microelectron ics. Such devices are not only important for applications but also for basic research. The pioneering work by Fowler, Fang, Howard and Stiles [l] has shown that new quantum phenomena become visible if the electrons of a conductor are confined within a typical length of 10 nm. Their discoveries opened the field of two-dimension al electron systems which since 1975 is the subject of a conference series [2]. It has been demonstrated that this field is important for the description of nearly all optical and electrical properties of microelectron ic devices. A two-dimensiona l electron gas is absolutely necessary for the observation of the Quantized Hall Effect, and the realization and properties of such a system will be discussed in section 2. In addition to the quantum phenomena connected with the confinement of electrons within a two-dimensional layer, another quantization - the Landau quantization of the electron motion in a strong magnetic field - is essential for the interpretation of the Quantized Hall Effect (section 3). Some experimental results will be summarized in section 4 and the application of the QHE in metrology is the subject of section 5.

489 citations


Journal ArticleDOI
Abstract: The electron drift‐velocity–electric‐field relationship has been calculated for the Ga1−xInxP1−yAsy quaternary alloy using the Monte Carlo method. Emphasis has been placed on the compositional range for which the alloy is lattice matched to GaAs and InP. These calculations suggest that this quaternary offers promise as a material for microwave semiconductor devices, including field‐effect transistors and transferred electron devices.

146 citations


Journal ArticleDOI
Abstract: Avalanche photodiodes for detection at 0.9–1.2 μm have been successfully fabricated in epitaxial layers of GaInAsP on InP substrates. Uniform avalanche gains in excess of 12, rise times of 150 psec or less, and low‐bias quantum efficiencies of 45% have been measured.

103 citations


Journal ArticleDOI
Abstract: The growth and operation of lattice‐matched double‐heterostructure InP/Ga0.17In0.83As0.34P0.66/InP light‐emitting diodes is reported. These diodes have an emission wavelength of 1.1 μm and quantum efficiencies of 4%.

80 citations


Journal ArticleDOI
Abstract: Cyclotron resonance and the magnetophonon effect have been used to measure the effective mass as a function of alloy composition for GaxIn1−xAsyP1−y samples grown lattice matched to InP. Values of ωτ of up to 6 allow an accurate measurement of effective mass, which is found to depend linearly upon alloy composition y with the relation m*/m0=0.080−0.039y. The observation of shallow impurity transitions in a quaternary alloy is also reported.

78 citations