Study of High-Frequency Performance in GeSn-Based QWIP
19 Dec 2019-pp 448-452
TL;DR: In this paper, the high-frequency performance of GeSn-SiGeSn QWIP has been studied considering the intersubband transition and transit time effect of electrons, and the band structure and the analytical results of responsivity are also presented.
Abstract: QWIP using group IV elements are of great research attention for its potential application in optical communication and in optical interconnects. The high-frequency performance of GeSn–SiGeSn QWIP has been studied considering the intersubband transition and transit time effect of electrons. The band structure of GeSn–SiGeSn QWIP and the analytical results of responsivity are also presented in this paper.
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IBM1
TL;DR: In this paper, a theoretical model is presented to predict the band offsets at both lattice-matched and pseudomorphic strained-layer interfaces, based on the local density functional pseudopotential formalism and the ''model solid approach'' of Van de Walle and Martin.
Abstract: Semiconductor heterojunctions and superlattices have recently shown tremendous potential for device applications because of their flexibility for tailoring the electronic band structure. A theoretical model is presented to predict the band offsets at both lattice-matched and pseudomorphic strained-layer interfaces. The theory is based on the local-density-functional pseudopotential formalism and the ``model-solid approach'' of Van de Walle and Martin. This paper is intended as a self-contained description of the model, suitable for practical application. The results can be most simply expressed in terms of an ``absolute'' energy level for each semiconductor and deformation potentials that describe the effects of strain on the electronic bands. The model predicts reliable values for the experimentally observed lineups in a wide variety of test cases and can be used to explore which combinations of materials and configurations of the strains will lead to the desired electronic properties.
1,807 citations
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TL;DR: The literature on quantum-well infrared photodetectors (QWIPs) is reviewed in this paper, where a detailed discussion is given on the device physics of the intersubband absorption and hot-carrier transport processes for individual detectors, as well as the high performance which has been achieved for large staring arrays.
Abstract: The extensive literature on quantum‐well infrared photodetectors (QWIPs) is reviewed. A detailed discussion is given on the device physics of the intersubband absorption and hot‐carrier transport processes for individual detectors, as well as the high performance which has been achieved for large staring arrays. QWIPs having widely different structures, materials, and spectral responses are covered, as is the optimization of the quantum‐well parameters for maximum performance.
1,471 citations
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PARC1
TL;DR: A theoretical study of the structural and electronic properties of pseudomorphic Si/Ge interfaces, in which the layers are strained such that the lattice spacing parallel to the interface is equal on both sides.
Abstract: We present a theoretical study of the structural and electronic properties of pseudomorphic Si/Ge interfaces, in which the layers are strained such that the lattice spacing parallel to the interface is equal on both sides. The self-consistent calculations, based on the local density functional and ab initio pseudopotentials, determine the atomic structures and strains of minimum energy, and the lineup of the Si and Ge band structures. The presence of the strains causes significant shifts and splittings of the bulk bands. We derive values for the band discontinuities for (001), (111), and (110) interfaces under different strain conditions, and discuss the validity of the density-functional methods for the analysis of the interface problem. Spin-orbit splitting effects in the valence bands are included a posteriori. We express our results in terms of discontinuities in the valence bands, and deformation potentials for the bulk bands, and compare them with recent experiments on Si/${\mathrm{Si}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{Ge}}_{\mathrm{x}}$ heterostructures.
1,108 citations
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TL;DR: In this paper, an empirical tight-binding method for tetrahedrally coordinated cubic materials is presented and applied to group-IV and III-V semiconductors, and the method extends existing calculations by the inclusion of all five $d$ orbitals per atom in the basis set.
Abstract: An empirical tight-binding method for tetrahedrally coordinated cubic materials is presented and applied to group-IV and III-V semiconductors. The present ${\mathrm{spds}}^{*}$ method extends existing calculations by the inclusion of all five $d$ orbitals per atom in the basis set. On-site energies and two-center integrals between nearest neighbors in the Hamiltonian are fitted to measured energies, pseudopotential results, and the free-electron band structure. We demonstrate excellent agreement with pseudopotential calculations up to about 6 eV above the valence-band maximum even without inclusion of interactions with more distant atoms and three-center integrals. The symmetry character of the Bloch functions at the $X$ point is considerably improved by the inclusion of $d$ orbitals. Density of states, reduced masses, and deformation potentials are correctly reproduced.
668 citations
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23 Jan 2003
TL;DR: In this paper, the authors introduce the theory of OPTICAL PROCESSES and its application in two-dimensional (2D) systems and demonstrate the effects of electrics on low-dimensional (low-DIMENSIONal) systems.
Abstract: 1 INTRODUCTION 2 CLASSICAL THEORY OF OPTICAL PROCESSES 3 PHOTONS 4 ELECTRON BAND STRUCTURE AND ITS MODIFICATIONS 5 INTERBAND AND IMPURITY ABSORPTIONS 6 EXCITONIC ABSORPTION 7 ABSORPTION AND REFRACTION IN AN ELECTRIC FIELD 8 INTERBAND MAGNETO-OPTICAL EFFECTS 9 FREE CARRIER PROCESSES 10 RECOMBINATION PROCESSES 11 INTRODUCTION TO TWO-DIMENSIONAL SYSTEMS 12 OPTICAL PROCESSES IN QUANTUM WELLS 13 EXCITONS AND IMPURITIES IN QUANTUM WELLS 14 OPTICAL PROCESSES IN QUANTUM WIRES AND DOTS 15 SUPERLATTICES 16 STRAINED LAYERS 17 EFFECTS OF ELECTRIC FIELD ON LOW DIMENSIONAL SYSTEMS
289 citations