Sitangshu Bhattacharya – författare

In recent years, with the advent of fine line lithographical methods, molecular beam epitaxy, organometallic vapour phase epitaxy and other experimental techniques, low dimensional structures having quantum confinement in one, two and three dimensions (such as ultrathin films, inversion layers, accumulation layers, quantum well superlattices, quantum well wires, quantum wires superlattices, magneto-size quantizations, and quantum dots) have attracted much attention not only for their potential in uncovering new phenomena in nanoscience and technology, but also for their interesting applications in the areas of quantum effect devices. In ultrathin films, the restriction of the motion of the carriers in the direction normal to the film leads to the quantum size effect and such systems find extensive applications in quantum well lasers, field effect transistors, high speed digital networks and also in other quantum effect devices. In quantum well wires, the carriers are quantized in two transverse directions and only one-dimensional motion of the carriers is allowed.

In recent years, with the advent of fine line lithographical methods, molecular beam epitaxy, organometallic vapour phase epitaxy and other experimental techniques, low dimensional structures having quantum confinement in one, two and three dimensions (such as ultrathin films, inversion layers, accumulation layers, quantum well superlattices, quantum well wires, quantum wires superlattices, magneto-size quantizations, and quantum dots) have attracted much attention not only for their potential in uncovering new phenomena in nanoscience and technology, but also for their interesting applications in the areas of quantum effect devices. In ultrathin films, the restriction of the motion of the carriers in the direction normal to the film leads to the quantum size effect and such systems find extensive applications in quantum well lasers, field effect transistors, high speed digital networks and also in other quantum effect devices. In quantum well wires, the carriers are quantized in two transverse directions and only one-dimensional motion of the carriers is allowed.

This monograph solely investigates the Debye Screening Length (DSL) in semiconductors and their nano-structures. The materials considered are quantized structures of non-linear optical, III-V, II-VI, Ge, Te, Platinum Antimonide, stressed materials, Bismuth, GaP, Gallium Antimonide, II-V and Bismuth Telluride respectively. The DSL in opto-electronic materials and their quantum confined counterparts is studied in the presence of strong light waves and intense electric fields on the basis of newly formulated electron dispersion laws that control the studies of such quantum effect devices. The suggestions for the experimental determination of 2D and 3D DSL and the importance of measurement of band gap in optoelectronic materials under intense built-in electric field in nano devices and strong external photo excitation (for measuring photon induced physical properties) have also been discussed in this context. The influence of crossed electric and quantizing magnetic fields on the DSL and the DSL in heavily doped semiconductors and their nanostructures has been investigated. This monograph contains 150 open research problems which form the integral part of the text and are useful for both PhD students and researchers in the fields of solid-state sciences, materials science, nano-science and technology and allied fields in addition to the graduate courses in modern semiconductor nanostructures.

This book presents the Einstein Relation(ER) in two-dimensional (2-D) Heavily Doped (HD) Quantized Structures. The materials considered are quantized structures of HD non-linear optical, III-V, II-VI, Ge, Te, Platinum Antimonide, stressed materials, GaP, Gallium Antimonide, II-V, Bismuth Telluride together with various types of HD superlattices and their Quantized counterparts respectively. The ER in HD opto-electronic materials and their nanostructures is studied in the presence of strong light waves and intense electric fields on the basis of newly formulated electron dispersion laws that control the studies of such quantum effect devices. The suggestion for the experimental determination of HD 2D and 3D ERs and the importance of measurement of band gap in HD optoelectronic materials under intense built-in electric field in nanodevices and strong external photo excitation (for measuring photon induced physical properties) are also discussed in this context. The influence of crossed electric and quantizing magnetic fields on the ER of the different 2D HD quantized structures (quantum wells, inversion and accumulation layers, quantum well HD superlattices and nipi structures) under different physical conditions is discussed in detail. This monograph contains 100 open research problems which form the integral part of the text and are useful for both Ph.D aspirants and researchers in the fields of condensed matter physics, solid-state sciences, materials science, nano-science and technology and allied fields.

This monograph solely investigates the Debye Screening Length (DSL) in semiconductors and their nano-structures. The materials considered are quantized structures of non-linear optical, III-V, II-VI, Ge, Te, Platinum Antimonide, stressed materials, Bismuth, GaP, Gallium Antimonide, II-V and Bismuth Telluride respectively. The DSL in opto-electronic materials and their quantum confined counterparts is studied in the presence of strong light waves and intense electric fields on the basis of newly formulated electron dispersion laws that control the studies of such quantum effect devices. The suggestions for the experimental determination of 2D and 3D DSL and the importance of measurement of band gap in optoelectronic materials under intense built-in electric field in nano devices and strong external photo excitation (for measuring photon induced physical properties) have also been discussed in this context. The influence of crossed electric and quantizing magnetic fields on the DSL and the DSL in heavily doped semiconductors and their nanostructures has been investigated. This monograph contains 150 open research problems which form the integral part of the text and are useful for both PhD students and researchers in the fields of solid-state sciences, materials science, nano-science and technology and allied fields in addition to the graduate courses in modern semiconductor nanostructures.

This book presents the Einstein Relation(ER) in two-dimensional (2-D) Heavily Doped (HD) Quantized Structures. The materials considered are quantized structures of HD non-linear optical, III-V, II-VI, Ge, Te, Platinum Antimonide, stressed materials, GaP, Gallium Antimonide, II-V, Bismuth Telluride together with various types of HD superlattices and their Quantized counterparts respectively. The ER in HD opto-electronic materials and their nanostructures is studied in the presence of strong light waves and intense electric fields on the basis of newly formulated electron dispersion laws that control the studies of such quantum effect devices. The suggestion for the experimental determination of HD 2D and 3D ERs and the importance of measurement of band gap in HD optoelectronic materials under intense built-in electric field in nanodevices and strong external photo excitation (for measuring photon induced physical properties) are also discussed in this context. The influence of crossed electric and quantizing magnetic fields on the ER of the different 2D HD quantized structures (quantum wells, inversion and accumulation layers, quantum well HD superlattices and nipi structures) under different physical conditions is discussed in detail. This monograph contains 100 open research problems which form the integral part of the text and are useful for both Ph.D aspirants and researchers in the fields of condensed matter physics, solid-state sciences, materials science, nano-science and technology and allied fields.

In recent years, with the advent of ?ne line lithographical methods, molecular beam epitaxy, organometallic vapour phase epitaxy and other experimental techniques, low dimensional structures having quantum con?nement in one, two and three dimensions (such as inversion layers, ultrathin ?lms, nipi's, quantum well superlattices, quantum wires, quantum wire superlattices, and quantum dots together with quantum con?ned structures aided by various other ?elds) have attracted much attention, not only for their potential in uncovering new phenomena in nanoscience, but also for their interesting applications in the realm of quantum e?ect devices. In ultrathin ?lms, due to the reduction of symmetry in the wave-vector space, the motion of the carriers in the direction normal to the ?lm becomes quantized leading to the quantum size e?ect. Such systems ?nd extensive applications in quantum well lasers, ?eld e?ect transistors, high speed digital networks and also in other low dimensional systems. In quantum wires, the carriers are quantized in two transverse directions and only one-dimensional motion of the carriers is allowed.The transport properties of charge carriers in quantum wires, which may be studied by utilizing the similarities with optical and microwave waveguides, are currently being investigated. Knowledge regarding these quantized structures may be gained from original research contributions in scienti?c journals, proceedings of international conferences and various - view articles.

In recent years, with the advent of ?ne line lithographical methods, molecular beam epitaxy, organometallic vapour phase epitaxy and other experimental techniques, low dimensional structures having quantum con?nement in one, two and three dimensions (such as inversion layers, ultrathin ?lms, nipi's, quantum well superlattices, quantum wires, quantum wire superlattices, and quantum dots together with quantum con?ned structures aided by various other ?elds) have attracted much attention, not only for their potential in uncovering new phenomena in nanoscience, but also for their interesting applications in the realm of quantum e?ect devices. In ultrathin ?lms, due to the reduction of symmetry in the wave-vector space, the motion of the carriers in the direction normal to the ?lm becomes quantized leading to the quantum size e?ect. Such systems ?nd extensive applications in quantum well lasers, ?eld e?ect transistors, high speed digital networks and also in other low dimensional systems. In quantum wires, the carriers are quantized in two transverse directions and only one-dimensional motion of the carriers is allowed.The transport properties of charge carriers in quantum wires, which may be studied by utilizing the similarities with optical and microwave waveguides, are currently being investigated. Knowledge regarding these quantized structures may be gained from original research contributions in scienti?c journals, proceedings of international conferences and various - view articles.

The merging of the concept of introduction of asymmetry of the wave vector space of the charge carriers in semiconductors with the modern techniques of fabric- ing nanostructured materials such as MBE, MOCVD, and FLL in one, two, and three dimensions (such as ultrathin ?lms, nipi structures, inversion and accumu- tion layers, quantum well superlattices, carbon nanotubes, quantum wires, quantum wire superlattices, quantumdots, magnetoinversionand accumulationlayers, qu- tum dot superlattices, etc. ) spawns not only useful quantum effect devices but also unearth new concepts in the realm of nanostructured materials science and related disciplines. It is worth remaking that these semiconductor nanostructures occupy a paramount position in the entire arena of low-dimensional science and technology by their own right and ?nd extensive applications in quantum registers, resonant tunneling diodes and transistors, quantum switches, quantum sensors, quantum logic gates, heterojunction ?eld-effect, quantum well and quantum wire trans- tors, high-speed digital networks, high-frequency microwave circuits, quantum cascade lasers, high-resolution terahertz spectroscopy, superlattice photo-oscillator, advanced integrated circuits, superlattice photocathodes, thermoelectric devices, superlattice coolers, thin ?lm transistors, intermediate-band solar cells, micro- tical systems, high-performanceinfrared imaging systems, bandpass ?lters, thermal sensors, optical modulators, optical switching systems, single electron/molecule electronics, nanotube based diodes, and other nanoelectronic devices.

This monograph solely presents the Fowler-Nordheim field emission (FNFE) from semiconductors and their nanostructures. The materials considered are quantum confined non-linear optical, III-V, II-VI, Ge, Te, carbon nanotubes, PtSb2, stressed materials, Bismuth, GaP, Gallium Antimonide, II-V, Bi2Te3, III-V, II-VI, IV-VI and HgTe/CdTe superlattices with graded interfaces and effective mass superlattices under magnetic quantization and quantum wires of the aforementioned superlattices. The FNFE in opto-electronic materials and their quantum confined counterparts is studied in the presence of light waves and intense electric fields on the basis of newly formulated electron dispersion laws that control the studies of such quantum effect devices. The importance of band gap measurements in opto-electronic materials in the presence of external fields is discussed from this perspective. This monograph contains 200 open research problems which form the very core and are useful for Ph. D students and researchers. The book can also serve as a basis for a graduate course on field emission from solids.

The merging of the concept of introduction of asymmetry of the wave vector space of the charge carriers in semiconductors with the modern techniques of fabric- ing nanostructured materials such as MBE, MOCVD, and FLL in one, two, and three dimensions (such as ultrathin ?lms, nipi structures, inversion and accumu- tion layers, quantum well superlattices, carbon nanotubes, quantum wires, quantum wire superlattices, quantumdots, magnetoinversionand accumulationlayers, qu- tum dot superlattices, etc. ) spawns not only useful quantum effect devices but also unearth new concepts in the realm of nanostructured materials science and related disciplines. It is worth remaking that these semiconductor nanostructures occupy a paramount position in the entire arena of low-dimensional science and technology by their own right and ?nd extensive applications in quantum registers, resonant tunneling diodes and transistors, quantum switches, quantum sensors, quantum logic gates, heterojunction ?eld-effect, quantum well and quantum wire trans- tors, high-speed digital networks, high-frequency microwave circuits, quantum cascade lasers, high-resolution terahertz spectroscopy, superlattice photo-oscillator, advanced integrated circuits, superlattice photocathodes, thermoelectric devices, superlattice coolers, thin ?lm transistors, intermediate-band solar cells, micro- tical systems, high-performanceinfrared imaging systems, bandpass ?lters, thermal sensors, optical modulators, optical switching systems, single electron/molecule electronics, nanotube based diodes, and other nanoelectronic devices.

The presence of intense electric field and the light waves change the band structure of optoelectronic semiconductors in fundamental ways, which have also been incorporated in the study of the EEM in quantized structures of optoelectronic compounds that control the studies of the quantum effect devices under strong fields.

This book deals with the Effective Electron Mass (EEM) in low dimensional semiconductors. The materials considered are quantum confined non-linear optical, III-V, II-VI, GaP, Ge, PtSb2, zero-gap, stressed, Bismuth, carbon nanotubes, GaSb, IV-VI, Te, II-V, Bi2Te3, Sb, III-V, II-VI, IV-VI semiconductors and quantized III-V, II-VI, IV-VI and HgTe/CdTe superlattices with graded interfaces and effective mass superlattices. The presence of intense electric field and the light waves change the band structure of optoelectronic semiconductors in fundamental ways, which have also been incorporated in the study of the EEM in quantized structures of optoelectronic compounds that control the studies of the quantum effect devices under strong fields. The importance of measurement of band gap in optoelectronic materials under strong electric field and external photo excitation has also been discussed in this context. The influence of crossed electric and quantizing magnetic fields on the EEM and the EEM in heavily doped semiconductors and their nanostructures is discussed. This book contains 200 open research problems which form the integral part of the text and are useful for both Ph. D aspirants and researchers in the fields of solid-state sciences, materials science, nanoscience and technology and allied fields in addition to the graduate courses in modern semiconductor nanostructures. The book is written for post graduate students, researchers and engineers, professionals in the fields of solid state sciences, materials science, nanoscience and technology, nanostructured materials and condensed matter physics.