Dynamics Contributions to the Growth Mechanism of Ga2O3 Thin Film and NWs Enabled by Ag Catalyst

Abstract

In the last few years, interest in the use of gallium oxide (Ga2O3) as a semiconductor for high power/high temperature devices and UV nano-sensors has grown. Ga2O3 has an enormous band gap of 4.8 eV, which makes it well suited for applications in harsh environments. In this work, we explored the effect of Ag thin film as a catalyst to grow gallium oxide. The growth of gallium oxide thin film and nanowires can be achieved by heating and oxidizing pure gallium at high temperatures (~1000 °C) in the presence of trace amounts of oxygen. We present the results of structural, morphological, and elemental characterization of the β-Ga2O3 thin film and nanowires. In addition, we explore and compare the sensing properties of the β-Ga2O3 thin film and nanowires for UV detection. The proposed process can be optimized to a high scale production Ga2O3 nanocrystalline thin film and nanowires. By using Ag thin film as a catalyst, we can control the growth parameters to obtain either nanocrystalline thin film or nanowires.

Comparative Study of Growth Morphologies of Ga2O3 Nanowires on Different Substrates

“…The growth morphologies of gallium oxide were studied on various substrates and at different oxidation temperatures. Previous work has shown that crystalline the Ga 2 O 3 phase was obtained under the same oxidation conditions used in this work [ 2 , 22 ]. Because the oxidation conditions were kept constant in this work, the nanostructures formed during oxidation are primarily related to the substrate.…”

“…During the oxidation of the substrates in the presence of Ag, additional temperature-dependent processes influenced both the nucleation and the growth of nanostructures. Ga 2 O 3 nucleation in the presence of Ag was greatly influenced by the oxidation temperatures due to the high oxygen diffusivity and solubility in silver at higher temperatures [ 2 , 22 ].…”

“…As a complete system of O–Ag–Ga, after Ag is incorporated into Ga, there is more oxygen in the system available to react with Ga, leading to denser and longer nanowires. At higher temperatures (T ≥ 1000 °C), Ga 2 O 3 nanowires continue to grow as the diffusivity and solubility of oxygen increases with temperature [ 2 ].…”

“…A number of growth techniques have been investigated by growing Ga 2 O 3 thin films and nanowires. These techniques involve thermal oxidation [ 2 ], pulsed laser deposition (PLD) [ 3 , 4 ], molecular beam epitaxy [ 5 , 6 ], metalorganic chemical vapor deposition [ 7 , 8 ] and hydrothermal synthesis [ 9 , 10 , 11 ].…”

The Growth of Ga2O3 Nanowires on Silicon for Ultraviolet Photodetector

“…The sensors obtained using this innovative approach will lead to new trends in design, control, and applications of real-time intelligent sensor system control by advanced intelligent control methods and techniques. The effect of Ag thin film as a catalyst to enhance the growth of Ga 2 O 3 nanowire and crystalline thin film on quartz has been reported [29], but it has not been explored on the silicon surface. We also wanted to observe the contribution of silicon atoms in enhancing the conductivity of Ga 2 O 3 nanowires via diffusion-enabled incorporation into the nanowires during the growth process.…”