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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TL;DR: In this article, a three-terminal Hanle effect measurement was performed on a high-quality epitaxial Schottky contacts on $n$-type Ge and the observed spin voltage was several orders of magnitude larger than predicted by the theory of spin injection and diffusive spin transport.
Abstract: Spin injection in high-quality epitaxial $\mathrm{M}{\mathrm{n}}_{5}\mathrm{G}{\mathrm{e}}_{3}$ Schottky contacts on $n$-type Ge has been investigated using a three-terminal Hanle effect measurement. Clear Hanle and inverted Hanle signals with features characteristic of spin accumulation and spin precession are observed up to 200 K. Strikingly, the observed spin voltage is several orders of magnitude larger than predicted by the theory of spin injection and diffusive spin transport. Since the devices have no oxide tunnel barrier, the discrepancy between theory and experiments cannot be explained by the often-invoked spin accumulation in localized states associated with the oxide or oxide/semiconductor interface. The observed spin voltages therefore must originate from the Ge itself, either from spins in the Ge bulk bands or its depletion region.
42 citations
TL;DR: In this article, the transition region analysis of an abrupt heterojunction is extended to include the effects of mobile carriers' charge in the space charge regions, and deviations from the depletion model are obtained when the wide band-gap semiconductor is heavier-doped.
Abstract: The transition region analysis of an abrupt heterojunction is extended to include the effects of mobile carriers‘ charge in the space charge regions. Deviations from the depletion model are obtained when the wide band-gap semiconductor is heavier-doped-This is due to a non-negligible potential drop across the narrow band-gap semiconductor at an isotype (i.e. n-n or p-p) heterojunction, and to an inversion layer at the interface in the same semiconductor at an anisotype (i.e. p-n or n-p) heterojunction. The C−2 versus V plots are acceptable, straight lines having slopes in agreement with the depletion model predictions, but the intercept voltages differ. A constant electric dipole at the interface causes a similar effect.
42 citations
TL;DR: In this article, a cross-form microchip is fabricated in which the two side channels are attached to the main channel via a nanochannel bridge, and the depletion and enrichment zones are established on the anodic and cathodic sides of the nanochannels.
Abstract: This study fabricates a cross-form microchip in which the two side channels are attached to the main channel via a nanochannel bridge Ionic depletion and enrichment zones are established on the anodic and cathodic sides of the nanochannel Results show that the low conductivity within the depletion zone induces a rapid electroosmotic flow, which in turn prompts the generation of vortex flow structures within the depletion zone Both the lengthening of the depletion bulk charge layer and decrease in length of the diffusion layer as the applied voltage is increased are also demonstrated in this study
42 citations
TL;DR: In this paper, the source-drain current and substrate current were investigated with and without illumination for both p-type and n-type Si substrates, and the decay time of the drain-source current indicates that the Si substrate, SiO2 layer, and metal electrode comprise a metal-oxide-semiconductor (MOS) capacitor due to the presence of defects at the interface between the substrate and SiO 2 layer.
Abstract: Graphene is a promising new material for photodetectors due to its excellent optical properties and high-speed response. However, graphene-based phototransistors have low responsivity due to the weak light absorption of graphene. We have observed a giant Dirac point shift upon white light illumination in graphene-based phototransistors with n-doped Si substrates, but not those with p-doped substrates. The source-drain current and substrate current were investigated with and without illumination for both p-type and n-type Si substrates. The decay time of the drain-source current indicates that the Si substrate, SiO2 layer, and metal electrode comprise a metal-oxide-semiconductor (MOS) capacitor due to the presence of defects at the interface between the Si substrate and SiO2 layer. The difference in the diffusion time of the intrinsic major carriers (electrons) and the photogenerated electron-hole pairs to the depletion layer delays the application of the gate voltage to the graphene channel. Therefore, th...
42 citations
TL;DR: In this paper, the authors developed a compact analytical model for the drain current of a silicon-on-insulator tunneling field effect transistor, which includes the effects of oxide thickness, body doping, drain voltage, and gate metal work function.
Abstract: In this paper, we have developed a compact analytical model for the drain current of a silicon-on-insulator tunneling field-effect transistor. The model includes the effects of oxide thickness, body doping, drain voltage, and gate metal work function. The model calculates the drain current using a tangent line approximation method to integrate the tunneling generation rate in the source–body depletion region. The accuracy of the model is tested against 2-D numerical simulations. The model predicts the drain current accurately in both the ON state (strong inversion) as well as in the subthreshold region.
42 citations