Role of Surface Chemistry of Ta Metal Foil on the Growth of GaN Nanorods by Laser Molecular Beam Epitaxy and Their Field Emission Characteristics.

This study investigates the influence of surface nitridation of Ta metal foil substrates on the growth of GaN nanorods using the laser molecular beam epitaxy (LMBE) technique and the field emission characteristics of the grown GaN nanorod ensemble. Surface morphology examinations underscore the pivotal role of Ta foil nitridation in shaping the dimensions and densities of GaN nanorods. Bare Ta foil fosters the formation of high-density, vertically self-aligned GaN nanorods at a growth temperature of 700 °C.

Phase-Dependent Dual Discrimination of MoSe/MoO Composites Toward ,-Dimethylformamide and Triethylamine at Room Temperature.

Herein, we present, a chemiresistive-type gas sensor composed of two-dimensional 1T-2H phase MoSe and MoO. Mixed phase MoSe and MoSe/MoO composites were synthesized via a facile hydrothermal method. The structure analysis using X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy revealed the formation of different phases of MoSe at different temperatures.

Highly Responsive Near-Infrared Si/SbSe Photodetector via Surface Engineering of Silicon.

The development of imaging technology and optical communication demands a photodetector with high responsiveness. As demonstrated by microfabrication and nanofabrication technology advancements, recent progress in plasmonic sensor technologies can address this need. However, these photodetectors have low optical absorption and ineffective charge carrier transport efficiency.

Flexible perylenediimide/GaN organic-inorganic hybrid system with exciting optical and interfacial properties.

We report the band gap tuning and facilitated charge transport at perylenediimide (PDI)/GaN interface in organic-inorganic hybrid nanostructure system over flexible titanium (Ti) foil. Energy levels of the materials perfectly align and facilitate high efficiency charge transfer from electron rich n-GaN to electron deficient PDI molecules. Proper interface formation resulted in band gap tuning as well as facilitated electron transport as evident in I-V characteristics.

Structural and Optical Properties of GaN Film on Copper and Graphene/Copper Metal Foils Grown by Laser Molecular Beam Epitaxy.

We report the direct growth of crystalline GaN on bare copper (Cu) and monolayer-graphene/Cu metal foils using laser molecular beam epitaxy technique at growth temperature of 700 °C. The surface morphology investigated with field emission scanning electron microscopy revealed that the size of GaN grains for film grown on bare Cu falls in range of 90 to 160 nm whereas large grains with size of ˜200 to 600 nm was obtained for GaN grown on graphene/Cu foil under similar growth condition. The transverse optical mode of cubic GaN and ₂ (high) phonon mode for wurtzite GaN phases were obtained on the GaN film grown on Cu and graphene/Cu metal foils as deduced by Raman spectroscopy.

Structural and Optical Properties of Self-Assembled Epitaxially Grown GaN Nanorods and Nanoporous Film on Sapphire (0001) Using Laser Molecular Beam Epitaxy.

The GaN nanoporous-film (NPF) and nanorods (NRs) were grown on sapphire (0001) using laserassisted molecular beam epitaxy (LMBE) technique by laser ablating solid GaN target at different laser energy density. The interconnected GaN NPF was grown at low laser energy density of ˜4 J/cm² whereas vertically aligned GaN NRs was obtained at high laser energy density of ˜7 J/cm². The pore size of the GaN NPF structure is in range of 40-120 nm.

Negative-capacitance and bulk photovoltaic phenomena in gallium nitride nanorods network.

An enhanced self-powered near-ultraviolet photodetection phenomenon was observed in epitaxial gallium nitride (GaN) nanorods network grown on an intermediate layer of N:GaN on a nitridated HfO(N:HfO)/SiO/p-Si substrate. The fabricated Au/GaN/N:GaN/N:HfO/Ag heterostructure exhibited a giant change (OFF/ON ratio > 50 without applying any external electrical field) in its conductance when illuminated by a very weak (25 mW cm) near-UV monochromatic light with a low dark current (nearly 20 nA). The presented near-UV photodetector offers photoresponsivity of ∼2.