p–n junction

About: p–n junction is a research topic. Over the lifetime, 7701 publications have been published within this topic receiving 108890 citations. The topic is also known as: p-n junction.

The channeling avalanche photodiode: A novel ultra-low-noise interdigitated p-n junction detector

Abstract: A novel avalanche photodiode (APD) concept, the channeling APD, is proposed. Using a new interdigitated p-n junction structure, electrons and holes are spatially separated and impact ionize in layers of different band gap. Thus the effective ionization-rates ratio can be made extremely high (κ = α/β > 100), while maintaining a high gain, by a proper choice of the band gap difference. In the limit of large κ, this device mimics a channeltron photomultiplier. This structure can be fabricated using most III-V lattice matched heterojunctions, including long-wavelength materials for fiber-optical communications ( 1.3 \leq \lambda µm). The design of three channeling APD's using Al 0.45 Ga 0.55 As/ GaAs, InP/In 0.53 Ga 0.47 As, and AlAs 0.08 Sb 0.92 /GaSb heterojunctions is discussed in detail. Other important features of this structure are the unique capacitance-voltage characteristic, which may be important in varactor diode applications, and the interdigitized geometry which allows the depletion of large volumes of semiconductor materials doped to levels as high as 1017/cm3. This novel semiconductor device may find interesting applications also for FET's and integrated p-i-n-FET receivers and may be used for studies of high-field transport phenomena (e.g., drift velocities) over a wide range of electric fields.

Highly Efficient Charge Separation and Collection across in Situ Doped Axial VLS-Grown Si Nanowire p–n Junctions

Abstract: VLS-grown semiconductor nanowires have emerged as a viable prospect for future solar-based energy applications. In this paper, we report highly efficient charge separation and collection across in situ doped Si p–n junction nanowires with a diameter <100 nm grown in a cold wall CVD reactor. Our photoexcitation measurements indicate an internal quantum efficiency of ∼50%, whereas scanning photocurrent microscopy measurements reveal effective minority carrier diffusion lengths of ∼1.0 μm for electrons and 0.66 μm for holes for as-grown Si nanowires (dNW ≈ 65–80 nm), which are an order of magnitude larger than those previously reported for nanowires of similar diameter. Further analysis reveals that the strong suppression of surface recombination is mainly responsible for these relatively long diffusion lengths, with surface recombination velocities (S) calculated to be 2 orders of magnitude lower than found previously for as-grown nanowires, all of which used hot wall reactors. The degree of surface passiva...

Diffusion length determination in p‐n junction diodes and solar cells

Abstract: An experimental technique for determining the minority carrier diffusion length in the base region of Si p‐n junction diodes and solar cells is described. The procedure is to operate the device in the photoconductive mode and to measure its photoresponse in the wavelength region near the energy gap. The ratio of incident light intensity to photocurrent is a linear function of reciprocal absorption coefficient for each wavelength; the slope of the set of points directly yields the diffusion length. In addition, a nonlinear least‐squares analysis is also used to determine the diffusion length.

Grain boundaries in p‐n junction diodes fabricated in laser‐recrystallized silicon thin films

Abstract: Grain boundaries intersecting metallurgical p‐n junctions have been evaluated in laser‐recrystallized silicon thin films. Lateral p‐n junction diodes were fabricated in islands of polycrystalline silicon which were defined on an amorphous substrate and cw laser recrystallized. The oxide‐passivated diodes display good current rectification. Correlated scanning electron microscopy (electron‐beam induced current and voltage contrast) and transmission electron microscopy reveal that the electrical junction strongly deviates from the linear boundary between the n and p regions defined by ion implantation. Spikes in the junction profile arise from enhanced dopant diffusion along grain boundaries.

Forward-voltage capacitance and thickness of p-n junction space-charge regions

Abstract: A comprehensive analytical model for the quasi-static capacitance of the space-charge region of p-n junction devices is presented. It describes the capacitance for all voltages, including voltages large enough to cause the junction barrier to vanish. The model applies for exponential-constant doping profiles, the limiting cases of which are the step and the linear-graded profiles. In addition to the analytical model, an iterative technique is developed to yield numerically the thickness of the space-charge region as a function of voltage. The capacitance model shows good agreement when compared with measured dependencies, With an empirical model for circuit simulation, and with models based on device simulation. The model extends previous replacements of the depletion capacitance, provides a tool for circuit simulation, and is intended to provide understanding of the physics related to storage of mobile holes and electrons in the junction space-charge region.