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, the authors used ion drift techniques to produce linear graded junctions whose gradients were between 1011 and 1014 atoms/cm3/cm, where the space charge of thermally generated carriers in the intrinsic region distorted the lithium ion distribution.
Abstract: p‐i‐n junctions were fabricated by ion‐drift techniques using lithium in p‐type silicon. Highly compensated intrinsic regions from 0.1 to 5.0 mm were obtained. At temperatures between 120° and 200°C, the space charge of thermally generated carriers in the intrinsic region distorted the lithium ion distribution, producing linear graded junctions whose gradients were between 1011 and 1014 atoms/cm3/cm. Room‐temperature capacitance measurements were used to determine the impurity distribution. Agreement was found between calculated and measured values of the impurity gradient. Precipitation of lithium ions in the intrinsic region was not observed.The increase of the direct current under reverse junction potential as a function of the increased width of the depletion region permitted measurement of the diffusion and depletion‐region‐generated current components. The value of the diffusion current component at any temperature was proportional to the resistivity of the p‐type silicon. The depletion‐region‐gener...
41 citations
TL;DR: The design of a two-dimensional MoS2/GaN van der Waals (vdWs) heterostructure photodetector consisting of few-layer p-type MoS 2 and very thin n-type GaN flakes is reported, exhibiting advantageous synergetic effect.
Abstract: Molybdenum disulfide (MoS2) as a typical two-dimensional (2D) transition-metal dichalcogenide exhibits great potential applications for the next-generation nanoelectronics such as photodetectors. However, most MoS2-based photodetectors hold obvious disadvantages including a narrow spectral response in the visible region, poor photoresponsivity, and slow response speed. Here, for the first time, we report the design of a two-dimensional MoS2/GaN van der Waals (vdWs) heterostructure photodetector consisting of few-layer p-type MoS2 and very thin n-type GaN flakes. Thanks to the good crystal quality of the 2D-GaN flake and the built-in electric field in the interface depletion region of the MoS2/GaN p-n junction, photogenerated carriers can be rapidly separated and more excitons are collected by electrodes toward the high photoresponsivity of 328 A/W and a fast response time of 400 ms under the illumination of 532 nm light, which is seven times faster than pristine MoS2 flake. Additionally, the response spectrum of the photodetector is also broadened to the UV region with a high photoresponsivity of 27.1 A/W and a fast response time of 300 ms after integrating with the 2D-GaN flake, exhibiting an advantageous synergetic effect. These excellent performances render MoS2/GaN vdWs heterostructure photodetectors as promising and competitive candidates for next-generation optoelectronic devices.
41 citations
TL;DR: In this article, the activation energy of the total measured dark current in each local region of the temperature bias parameter space is evaluated and it is shown that the depletion region resides almost entirely within the absorber.
Abstract: Mid-wavelength infrared nBn detectors built with III–V superlattice materials have been tested by means of both capacitance and direct-current methods. By combining the results, it is possible to achieve clear separation of the two components of dark current, namely the generation–recombination (GR) current due to the Shockley–Read–Hall mechanism in the depletion region, and the diffusion current from the neutral region. The GR current component is unambiguously identified by two characteristics: (a) it is a linear function of the depletion width, and (b) its activation energy is approximately one-half the bandgap. The remaining current is shown to be due to diffusion because of its activation energy equaling the full bandgap. In addition, the activation energy of the total measured dark current in each local region of the temperature–bias parameter space is evaluated. We show the benefits of capacitance analysis applied to the nBn device and review some of the requirements for correct measurements. The carrier concentration of the unintentionally doped absorber region is found to be 1.2 × 1014 cm−3 n-type. It is shown that the depletion region resides almost entirely within the absorber. Also, the doping in the nBn barrier is found to be 4 × 1015 cm−3 p-type. Minority-carrier lifetimes estimated from the dark current components are on the order of 10 μs.
41 citations
TL;DR: In this paper, a high quality sandwich device was fabricated from wheat DNA molecular film by solution processing located between Au and n-type silicon inorganic semiconductor, and the electrical characteristics of the device such as currentvoltage and capacitance-voltage at room temperature were performed.
Abstract: High quality sandwich device was fabricated from wheat DNA molecular film by solution processing located between Au and n-type silicon inorganic semiconductor. We have performed the electrical characteristics of the device such as current–voltage (I–V) and capacitance–voltage (C–V) at room temperature. DNA-based on this structure showed an excellent rectifying behavior with a typical ideality factor of 1.22, and that DNA film increased the effective barrier height by influencing the space charge region of Si. We proposed that DNA could be an insulatorlike material with a wide optical band energy gap of 4.19 eV from its optical absorbance characteristics. Additionally, the energy distribution of interface state density, determined from the forward bias I–V characteristics by taking into account the bias dependence of the effective barrier height, decreases exponentially with bias from 7.48×1015 m−2 eV−1 in (Ec−0.40) eV to 8.56×1014 m−2 eV−1 in (Ec−0.72) eV.
41 citations
TL;DR: In this article, the authors show that the formation of a surface-near impurity depletion zone is inhibited by the very high diffusivity of oxygen in the Nb host crystal which kicks in at annealing temperatures as low as a few hundred degree Celsius.
Abstract: We have studied cleaning procedures of Nb(110) by verifying the surface quality with low-energy electron diffraction, Auger electron spectroscopy, and scanning tunneling microscopy and spectroscopy. Our results show that the formation of a surface-near impurity depletion zone is inhibited by the very high diffusivity of oxygen in the Nb host crystal which kicks in at annealing temperatures as low as a few hundred degree Celsius. Oxygen can be removed from the surface by heating the crystal up to $T=2400{\phantom{\rule{0.16em}{0ex}}}^{\ensuremath{\circ}}\mathrm{C}$. Tunneling spectra measured on the clean Nb(110) surface exhibit a sharp conductance peak in the occupied states at an energy of about $\ensuremath{-}450$ meV. Density functional theory calculations show that this peak is caused by a ${d}_{{z}^{2}}$ surface resonance band at the $\overline{\mathrm{\ensuremath{\Gamma}}}$ point of the Brillouin zone which provides a large density of states above the sample surface. The clean Nb(110) surface is superconducting with a gap width and a critical magnetic field strength in good agreement to the bulk value. In an external magnetic field we observe the Abrikosov lattice of flux quanta (vortices). Spatially resolved spectra show a zero-bias anomaly in the vortex core.
41 citations