【Device Papers】Growth and characterization of GaN/Ga₂O₃ nanowire heterostructures for ultraviolet optoelectronics

      Researchers from Latvijas Universitāte have published a dissertation titled " Growth and characterization of GaN/Ga₂O₃ nanowire heterostructures for ultraviolet optoelectronics " in Journal of Applied Physics.

Abstract

      Ultraviolet-range GaN/β-Ga₂O₃ heterostructures were fabricated and investigated in both planar and nanowire geometries using pulsed laser deposition and reactive magnetron sputtering from a liquid gallium target for β-Ga₂O₃ deposition, while both GaN nanowire arrays and planar p-type Mg-doped GaN layers were grown by metal-organic chemical vapor deposition. Precise control of film uniformity and thickness was achieved as confirmed by structural and morphology studies using x-ray diffraction, x-ray photoelectron spectroscopy, atomic force microscopy, and scanning electron microscopy. Planar n-Ga₂O₃/p-GaN heterojunction diodes were electrically and photoelectronically characterized, exhibiting pronounced rectifying behavior, high forward current and a visible-blind ultraviolet photoresponse under zero external bias, demonstrating intrinsic self-powered operation. Furthermore, GaN/β-Ga₂O₃ core/shell nanowire heterostructures were developed and systematically studied with a focus on morphology control and process optimization. The influence of deposition parameters on shell thickness, uniformity, and tapering was investigated, enabling improved conformality of the β-Ga₂O₃ coating on the M-plane facets of GaN nanowires. The results highlight the viability of physical vapor deposition techniques for forming GaN/β-Ga₂O₃ heterostructures and establish a pathway toward nanowire-based ultraviolet optoelectronic devices.

DOI：

https://doi.org/10.1063/5.0332647