Nanofunctional gallium oxide (Ga₂O₃) nanowires/nanostructures and their applications in nanodevices

Abstract

A brief review on beta gallium oxide (β‐Ga2O3) nanowires (NWs) and nanostructures (NS) is presented in this article. β‐Ga2O3 is a wide‐bandgap (Eg ∼ 4.9 eV) semiconductor and can be doped with n‐ and p‐type dopants, which can lead to applications in many functional devices. Here, we will first discuss briefly the properties of β‐Ga2O3 in bulk form. Then we will describe the growth of β‐Ga2O3 NWs/NS using various techniques including thermal CVD, MOCVD and laser ablation. The present status of research in the area of nanowire growth will be highlighted in this section. Then we will describe the luminescence properties of β‐Ga2O3 NWs such as photoluminescence (PL) and cathodoluminescence (CL). The origin of various peaks in the PL and CL spectra of β‐Ga2O3 NWs/ NS will be presented, with reference to various experimental studies carried out recently. In the final section, we will describe various applications of β‐Ga2O3 NWs in nanodevices such as field effect transistors (FET), gas sensors and deep‐UV photodetectors. Finally, we will give a conclusion and future perspective of the research in the area of this important semiconducting oxide. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Self‐Catalytic Growth of β‐Ga2O3 Nanostructures by Chemical Vapor Deposition

“…[1] In addition, it is n-type and transparent semiconductor with a direct bandgap of 4.9 eV at room temperature (RT). [1,2] The n-type semiconducting nature of b-Ga 2 O 3 is due to excess oxygen vacancies, which serve as shallow donors with ionization energy 30-40 meV. [3] The fabrication of b-Ga 2 O 3 nanostructures have recently attracted much attention owing to their applications in novel nanofunctional devices such as Ga 2 O 3 NW-based field effect transistors (FET), nano-photonic switches, deep UV photodetectors, and gas sensors.…”

High electron mobility thin-film transistors based on Ga2O3 grown by atmospheric ultrasonic spray pyrolysis at low temperatures

“…One wide bandgap metal oxide material that has been largely ignored is gallium oxide (Ga 2 O 3 ), with only a handful of reports on its use as an active element in TFTs. [22][23][24] Ga 2 O 3 is generally considered to exhibit semiconducting properties only above 500 C (Ref. 25) due to an oxygen deficit occurring at these temperatures, and as a result it has been investigated as the active material for high temperature oxygen sensors.…”

Emission properties of Ga2O3 nano-flakes: effect of excitation density

“…Depending on samples growth conditions and doping, there have been reported several broad PL peaks with positions ranged in the energy interval of ~1.7–3.8 eV131415161718192021. Below we summarize briefly some assignments of the luminescence in β -Ga 2 O 3 .…”