Depletion region

About: Depletion region is a research topic. Over the lifetime, 9393 publications have been published within this topic receiving 145633 citations.

A mechanism of degradation in leakage currents through ZnO varistors

Abstract: Thermally stimulated currents through ZnO varistors subjected to the voltage stresses, dc, and square‐wave voltages are analyzed on the base of carrier trappings in the depletion layers of ZnO grains. The analysis indicates that the field ionization of trapped carriers in a reverse‐biased depletion layer plays an important role in the degradation phenomena, thereby suggesting that the current increase with time under the dc and ac stresses is due to the same origin. An Arrhenius relation to predict the life of varistors and a dependence of leakage current Jc on time t, ln Jc ∝t1/2, are derived from a carrier trapping model.

Carrier transport mechanisms of p-type amorphous-n-type crystalline silicon heterojunctions

Abstract: Measured current–voltage characteristics of undoped and p‐type hydrogenated amorphous silicon (a‐Si:H)/n‐type crystalline silicon (c‐Si) heterojunctions are used to discuss the carrier transport mechanisms. The forward current was characterized by two parts: The forward current increased with applied voltage exponentially (region 1), and nonexponentially (region 2). In region 1, it was found that the current was dominated by the tunneling process in which electrons tunneled from the c‐Si into gap states in the a‐Si:H and recombinated holes captured by the gap states in the a‐Si:H. In region 2, the current was found to be a space‐charge‐limited current due to both electrons injected from the c‐Si and holes injected from an ohmic contact. The carrier transport mechanism of reverse currents depended on the magnitude of boron doping in the a‐Si:H. The reverse current was considered to be mainly generated in the depletion layer of the a‐Si:H for the heterojunction with undoped a‐Si:H, generated in the depletion layer of both the a‐Si:H and the c‐Si for that with boron‐doped a‐Si:H of B2H6/SiH4=1×10−5, and generated in the depletion layer of the c‐Si for that with boron‐doped a‐Si:H of B2H6/SiH4=1×10−4.

OBSERVATION OF THE DIELECTRIC‐WAVEGUIDE MODE OF LIGHT PROPAGATION IN p‐n JUNCTIONS

Abstract: Theoretical considerations of the propagation of electromagnetic energy near a p-n junction (1) show that the “sandwich” formed by having a depletion layer bounded by the p and n regions can act as a dielectric waveguide. (1,2)

Capacitance measurements of p-n junctions: depletion layer and diffusion capacitance contributions

Abstract: A set of capacitance measurements is proposed to identify the different contributions to the junction capacitance (diffusion capacitance and depletion layer capacitance) of p-n Si diodes. By measuring the C-f and C-V characteristics of Si commercial diodes, we fully characterize the AC behaviour of such devices. At reverse bias voltages, only the depletion layer capacitance is present and it is frequency independent in our range of measurement (up to 13 MHz). From C-V characteristics, we deduce a linearly graded junction nature and a built-in value of 0.59 ± 0.02 V. At forward bias voltages and frequencies lower than 100 kHz, both the diffusion and the depletion layer capacitances contribute to the junction capacitance. A simple calculation allows us to obtain a value for the average minority carrier lifetime of tau = (4 ± 2) × 10-6 s. Finally, a voltage dependence of exp(qV/2kT) is deduced for the diffusion capacitance.