TITLE:
Effect of Heat Treatment of Al Substrate on GaN Film Electrodeposited in Aqueous Solution
AUTHORS:
Jae-Wook Kang, Kensuke Kuroda, Masazumi Okido
KEYWORDS:
Gallium Nitride, Electrochemical Deposition, Growth from Aqueous Solutions, Aluminum Substrates
JOURNAL NAME:
Journal of Surface Engineered Materials and Advanced Technology,
Vol.10 No.1,
January
31,
2020
ABSTRACT: Most reports on the
fabrication of high-quality Gallium nitride (GaN) are typically based on
physical techniques that require very expensive equipment. Therefore, the
electrodeposition was adopted and examined to develop a simple and economical
method for GaN synthesis. GaN films are synthesized on aluminum substrates that
are heat-treated at various temperatures using a low-cost and low-temperature
electrochemical deposition technique. The electrochemical behavior of source
ions in aqueous solutions is examined by cyclic
voltammetry (CV).In the solution at pH 1.5 containing 0.1M
Ga(NO3)3, 2.5 M NH4NO3 and 0.6 M H3BO3,
reduction of gallium and nitrate ions are observed in CV. The presence of
hexagonal GaN and gallium oxide (Ga2O3) phases is
detected for the films deposited on Al substrates at -3.5 mA•cm-2 for 3 h. The energy dispersive X-ray and mapping results reveal that Ga, O, and
N coexist in these films. Raman analysis shows hexagonal GaN formation on Al substrates. The changes in the morphology and preferred orientation of GaN were found, which was caused by the reactivity of aluminum surface and the
aluminum oxide layer formed by the heat treatment.