Topic
Depletion region
About: Depletion region is a research topic. Over the lifetime, 9393 publications have been published within this topic receiving 145633 citations.
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52 citations
TL;DR: In this article, a numerical model based on drift-diffusion carrier transport is used for graded-junction bipolar transistors to evaluate electron injection across abrupt emitter-base heterojunctions by numerically solving the wave equation.
Abstract: The DC common-emitter current gains of abrupt- and graded-junction heterojunction bipolar transistors (HBTs) are studied and compared by numerical simulation. Electron injection across abrupt emitter-base heterojunctions is evaluated by numerically solving the wave equation. A numerical model based on drift-diffusion carrier transport is used for graded-junction HBTs and to assess recombination currents in both the structures. The results demonstrate that the increase in injected electron current afforded by compositional grading is accompanied by an increase in recombination within the space-charge layer. As a result, neither design option has a clear advantage with respect to common-emitter current gain. >
52 citations
TL;DR: In this paper, the authors present a consistent quantitative theory of the operation of a Geis-Spindt diamond field emitter, which is predicated on nearly zero field conditions in the diamond beyond the depletion layer, quasiballistic transport in the conduction band, and applicability of a modified Fowler-Nordheim equation to the transmission of electrons through the Schottky barrier at the metal-diamond interface.
Abstract: Recently, Geis et al. [J. Vac. Sci. Technol. B 14, 2060 (1996)] proposed a cold cathode emitter based on a Spindt-type design using a diamond film doped by substitutional nitrogen. The device is characterized by high field emission currents at very low power. Two properties, the rough surface of the metallic injector and the negative electron affinity of the (111) surface of the diamond are essential for its operation. We present a first consistent quantitative theory of the operation of a Geis–Spindt diamond field emitter. Its essential features are predicated on nearly zero-field conditions in the diamond beyond the depletion layer, quasiballistic transport in the conduction band, and applicability of a modified Fowler–Nordheim equation to the transmission of electrons through the Schottky barrier at the metal-diamond interface. Calculated results are in good qualitative and quantitative agreement with the experimental results of Geis et al.
52 citations
TL;DR: In this article, the Coulomb attraction between charged impurities present in the depletion zone of the Schottky contact and the charges accumulated in the metal at the interface with the semiconductor is considered.
Abstract: The converse electromechanical response in an organic Schottky contact follows a power law dependence S∝Vα of the mechanical strain S versus the applied voltage V, with an exponent α=1.5, in between linear piezoelectricity and quadratic electrostriction. The experimental result is discussed within the frame of a model, where the Coulomb attraction between charged impurities present in the depletion zone of the Schottky contact and the charges accumulated in the metal at the interface with the semiconductor is considered. Electromechanical responses of such devices appear to be of fundamental interest for the investigation of nonuniform electric field distributions and for potential practical applications as electromechanical transducers.
52 citations
TL;DR: In this paper, a comprehensive study on in-situ As doping of poly-crystalline CdTe solar cells by MOCVD was conducted, whereby high acceptor densities, approaching 3'×'1016 cm−3 were achieved at low growth temperature of 390'°C.
52 citations