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Abstract: The model for amorphous semiconductor InSb (a-InSb) was constructed through the first principles calculations, based on the idea of “continuous random networks” (CRN). The results of structural parameters for a-InSb are in agreement with the available data both theoretically and experimentally. The structure of a-InSb is almost tetrahedrally bonded with a perfect average coordination number of four. Due to the influence of the disorders, the density of states for a-InSb has the smearing structure in contrast to crystalline InSb (c-InSb). As a consequence of the induction of disorders, modification phenomena occur at the band edge of a-InSb in contrast to that of c-InSb. [Copyright &y& Elsevier]

Abstract: Near-field effect has been recognized to play an important role in optical coupling of multiple quantum well infrared photodetectors (QWIP). Both the optical near-field effect and the plasmonic effect in the quantum well active region of QWIP device have been studied by the finite difference time-domain (FDTD) method at the optical frequency of 4.2THz. Our numerical results indicate that both the near-field effect and the plasmonic effect can induce an evanescent wave with the electrical component being parallel to the growth direction of quantum well. The induced electrical component in the QWIP growth direction is 2.5 times larger than that of the incident optical fields. The induced polarization can increase the optical coupling efficiency of QWIP and the detectivity of QWIP can be improved at 4.2THz. [Copyright &y& Elsevier]