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.

Barrier accumulation-mode MOSFET

Abstract: In a trench-gated MOSFET, a lightly doped drift region of the N-type drain lies in the mesa between the trenches. The gate is doped with N-type material so that depletion regions are formed in the drift region when the gate voltage is equal to zero. The depletion regions merge at the center of the mesa, pinching off the flow of current when the device is turned off. This current-pinching effect allows the P-type body region to be made shallower and doped more lightly than usual without creating a punchthrough problem, because the barrier represented by the depletion regions adds to the normal current blocking capability of the PN junction between the body and drain regions. When the device is turned on by biasing the gate to a positive voltage, a low resistance accumulation layer forms in the drift region adjacent the trenches.

P-N Junction Charge-Storage Diodes

Abstract: The design theory for a new range of p-n junction applications is presented. The applications include pulse generation, wave shaping, and harmonic generation. The diodes are characterized by a very abrupt interruption of reverse current in the turn-off transient and are approximately ideal nonlinear capacitors. The abrupt interruption of current in the reverse transient is related to the impurity profile in the junction. An estimate is given of the duration of the abrupt phase. In addition, the role of parasitic elements such as inductance, capacitance, and series resistance is discussed in relation to a particular representative circuit. In typical cases, the abrupt turn-off phase lasts for a time of the order of 10-9 sec. Transitions in excess of 100 v or an ampere are readily obtained.

Imaging of built-in electric field at a p-n junction by scanning transmission electron microscopy.

Abstract: Precise measurement and characterization of electrostatic potential structures and the concomitant electric fields at nanodimensions are essential to understand and control the properties of modern materials and devices. However, directly observing and measuring such local electric field information is still a major challenge in microscopy. Here, differential phase contrast imaging in scanning transmission electron microscopy with segmented type detector is used to image a p-n junction in a GaAs compound semiconductor. Differential phase contrast imaging is able to both clearly visualize and quantify the projected, built-in electric field in the p-n junction. The technique is further shown capable of sensitively detecting the electric field variations due to dopant concentration steps within both p-type and n-type regions. Through live differential phase contrast imaging, this technique can potentially be used to image the electromagnetic field structure of new materials and devices even under working conditions.

Chemical Vapor Deposition of α -Boron Layers on Silicon for Controlled Nanometer-Deep p + n Junction Formation

Abstract: Nanometer-thick amorphous boron (?-B) layers were formed on (100) Si during exposure to diborane (B2H6) in a chemical vapor deposition (CVD) system, either at atmospheric or reduced pressures, at temperatures down to 500°C. The dependence of the growth mechanism on processing parameters was investigated by analytical techniques, such as transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS), in conjunction with extensive electrical characterization. In particular, devices fabricated by B deposition effectively demonstrated that p + doping of the silicon substrate can be achieved within 10 nm from the surface in a manner that is finely controlled by the B2H6 exposure conditions. High-quality, extremely ultrashallow, p + n junctions were fabricated, and their saturation current was tuned from high Schottky-like values to low deep pn junction-like values by the increasing of the deposited B layer thickness. This junction formation exhibited high selectivity, isotropy, spatial homogeneity, and compatibility with standard Si device fabrication.

Ultrasensitive Phototransistor Based on WSe2–MoS2 van der Waals Heterojunction

Abstract: Band engineering using the van der Waals heterostructure of two-dimensional materials allows for the realization of high-performance optoelectronic devices by providing an ultrathin and uniform PN junction with sharp band edges In this study, a highly sensitive photodetector based on the van der Waals heterostructure of WSe2 and MoS2 was developed The MoS2 was utilized as the channel for a phototransistor, whereas the WSe2-MoS2 PN junction in the out-of-plane orientation was utilized as a charge transfer layer The vertical built-in electric field in the PN junction separated the photogenerated carriers, thus leading to a high photoconductive gain of 106 The proposed phototransistor exhibited an excellent performance, namely, a high photoresponsivity of 2700 A/W, specific detectivity of 5 × 1011 Jones, and response time of 17 ms The proposed scheme in conjunction with the large-area synthesis technology of two-dimensional materials contributes significantly to practical photodetector applications