Effect of substrate temperature on the properties of spray deposited Ga2O3 thin films, for solar blind UV detector applications

Electrophoretic Deposition of Conformal β-Ga2O3 Films on Arbitrary Substrates for Heterojunction-Based Deep-Ultraviolet Photodetectors

“…Attempts of making β-Ga 2 O 3 films via the sol–gel method include sol-making, multiple spin-coating steps, and low-temperature heating (∼100 °C) to evaporate solvent, followed by high-temperature annealing (500–1100 °C) to allow film crystallization. It was observed that sol–gel-synthesized β-Ga 2 O 3 films postannealed below 700 °C show amorphous behavior, and the polycrystalline nature begins to appear above 700 °C. , The low-cost spray-pyrolysis-assisted synthesis of β-Ga 2 O 3 films resulted in the formation of both amorphous and polycrystalline films, and the crystalline nature of the as-deposited films is strongly dependent on the growth conditions, choice of precursors, and postannealing treatment conditions. − The nature of the crystallinity in β-Ga 2 O 3 films has a direct impact on their optoelectronic properties. For example, an abrupt change in bandgap of 0.61 eV and an increase in cathodoluminescence emission intensity are observed for β-Ga 2 O 3 films deposited at a substrate temperature of 350 °C vs 380 °C, which clearly shows a transition from an amorphous to polycrystalline structure …”

The Influence of Process Parameters on the Microstructural Properties of Spray-Pyrolyzed β-Ga2O3

“…The techniques established for obtaining the β-Ga 2 O 3 layers include, for instance, chemical vapor deposition [10], plasma-enhanced chemical vapor deposition [11,12], electron beam deposition [7], molecular beam epitaxy [13], pulsed laser deposition [14], radio-frequency magnetron sputtering [15], sol-gel [16], and hydro-and solvothermal methods [17][18][19]. However, low-cost techniques, such as ultrasonic nebulization and spray coating, are only represented in a few studies [20][21][22][23][24][25][26][27][28][29][30][31][32]. The latest reviews about β-Ga 2 O 3 rarely consider spray pyrolysis as a deposition method [1,33,34].…”