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.

Photocurrent generation in lateral graphene p-n junction created by electron-beam irradiation.

Abstract: Graphene has been considered as an attractive material for optoelectronic applications such as photodetectors owing to its extraordinary properties, e.g. broadband absorption and ultrahigh mobility. However, challenges still remain in fundamental and practical aspects of the conventional graphene photodetectors which normally rely on the photoconductive mode of operation which has the drawback of e.g. high dark current. Here, we demonstrated the photovoltaic mode operation in graphene p-n junctions fabricated by a simple but effective electron irradiation method that induces n-type doping in intrinsic p-type graphene. The physical mechanism of the junction formation is owing to the substrate gating effect caused by electron irradiation. Photoresponse was obtained for this type of photodetector because the photoexcited electron-hole pairs can be separated in the graphene p-n junction by the built-in potential. The fabricated graphene p-n junction photodetectors exhibit a high detectivity up to ~3 × 1010 Jones (cm Hz1/2 W−1) at room temperature, which is on a par with that of the traditional III–V photodetectors. The demonstrated novel and simple scheme for obtaining graphene p-n junctions can be used for other optoelectronic devices such as solar cells and be applied to other two dimensional materials based devices.

Highly rectifying Pr0.7Ca0.3MnO3∕SrTi0.9998Nb0.0002O3 p-n junction

Abstract: We have fabricated epitaxial Pr07Ca03MnO3∕SrTi09998Nb00002O3 (PCMO∕Nb:STO) junctions and characterized the interface electronic properties The PCMO∕Nb:STO junctions show highly rectifying current density–voltage (J–V) characteristics without an apparent breakdown in the reverse bias up to 100V at room temperature The J–V characteristics of the diodes agree well with the conventional diffusion theory for a p-n diode The forward bias J–V and reverse bias capacitance-voltage characteristics result in an identical built-in potential of ∼07eV Based on the experimental results, a plausible band diagram of the PCMO∕Nb:STO p-n diode is proposed

Tuning the charge transfer route by p–n junction catalysts embedded with CdS nanorods for simultaneous efficient hydrogen and oxygen evolution

Abstract: Overall solar water splitting into H2 and O2 using visible light responsive photocatalyst has been considered as a clean, green, and renewable system. CdS with a suitable bandgap (2.25 eV) and band position was for a long time not considered as a promising candidate for overall solar water splitting because of its serious photo-corrosion and rapid charge recombination, although it has considerable photocatalytic activity for H2 generation in a sacrificial agent containing electrolyte. Here, we design a new sandwich-like architecture using CdS nanorods embedded in a p–n junction of MoS2/N-RGO which serves as a novel photocatalytic system that could promote overall water splitting in natural water. It was found that the p–n junction of MoS2/N-RGO not only works as the HER and OER electrocatalyst for H2 and O2 generation respectively, but also facilitates charge separation by its inner electric field. Compared to well-defined thermodynamically favored charge transport, the new charge transfer route in MoS2/CdS/N-RGO splits natural water, resulting in an essential change of the carrier separation mechanism and high anti-corrosion.

Semiconductor devices controlled by depletion regions

Abstract: A field effect semiconductor device and method of controlling the device by merged depletion regions are provided. The device includes, in combination, first (22) and second (24) spaced apart PN junctions. Depletion regions (36, 38 and 40, 42) associated with the junctions have boundaries displaced from their respective junctions as a function of the doping concentration on either side of the junctions. The junctions are spaced apart by a distance with allows overlap of the depletion regions (38, 40) positioned therebetween. By applying a reverse bias to one (22) of the PN junctions the conductivity on the side (34) of the second PN junction (24) remote from the first PN junction (22) can be varied through the effect of merged depletion regions.