In this paper, we demonstrate an ultraviolet photodetector (UV-PD) that uses coalesced gallium nitride (GaN) nanorods (NRs) on a graphene/Si (111) substrate grown by plasma-assisted molecular beam epitaxy. We report a highly sensitive, self-powered, and hybrid GaN NR/graphene/Si (111) PD with a relatively large 100 mm 2 active area, a high responsivity of 17.4 A/W, a high specific detectivity of 1.23 Â 10 13 Jones, and fast response speeds of 13.2/13.7 ls (20 kHz) under a UV light of 355 nm at zero bias voltage. The results show that the thin graphene acts as a perfect interface for GaN NRs, encouraging growth with minimum defects on the Si substrate. Our results suggest that the GaN NR/graphene/Si (111) heterojunction has a range of interesting properties that make it well-suited for a variety of photodetection applications.

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Molybdenum disulfide (MoS2) has been attracting much attention due to its excellent electrical and optical properties. We successfully grew high-quality, large-area and uniform few-layer (FL)-MoS2 on p-doped Gallium Nitride (p-GaN)...

Nanocrystal interfaces can strongly influence the optical and electrical properties and charging trapping phenomena observed on oxide nanocrystal ensembles. The well-defined shape and controllable size distributions of MgO nanocrystals are a convenient system for studying these effects. Therefore, in the present work focused on the effect of temperature on the optical and electrical properties of magnesium oxide (MgO) nanocrystals, together with the responsible atomic centers, the bulk MgO is a study based on the first principle functional density theory (DFT) using PBE-GGA approximations. The absorption coefficient shows that MgO shows good coverage in the ultraviolet range. The bulk MgO is a direct bandgap nanocrystal at G point in the Brillion Zone despite the temperature applied values. The temperature is applied to alter the bandgap pattern and closes the bandgap at a high temperature. The PDOS and imaginary part of the dielectric function further confirm the insulator properties of the observed bandgap. Our results show that the optical properties are affected by the inconsistent temperature manners despite the different temperatures given to the system. Our absorption curve confirms that the nanocrystal is a good candidate for ultraviolet device application with a significantly high reflectivity percentage.