Low-temperature synthesis of GaN film from aqueous solution by electrodeposition
Gallium nitride (GaN) films were synthesized on n-type-Si (111) substrates using a low-cost and low-temperature technique of electrochemical deposition. The electrochemical behavior of Ga3+, NH4+, and NO3− ions in the aqueous solutions used as sources of GaN were confirmed by cyclic voltammetry. The scanning electron microscopy images showed that the films deposited at a current density of 3.5 mA cm−2 or greater have plate-like surface morphologies on the Si substrate. The energy-dispersive X-ray spectroscopy results showed that oxygen, gallium, and nitrogen coexist in these plate-like films. In the X-ray diffraction patterns, the sample synthesized at a current density of 3.5 mA cm−2 for 24 h exhibited peaks of gallium oxide and hexagonal-GaN phase. Photoluminescence analysis revealed a peak at 3.2 eV, which corresponds to the band gap energy of GaN, as well as a broad peak at around 2.5 eV at room temperature.
KeywordsElectrochemical deposition Cyclic voltammetry GaN Photoluminescence Low-cost technique
We appreciate the assistance offered by H. Amano and Y. Honda of Nagoya University with experiments for PL measurement. This work was financially supported by the Grant-in-Aid for Challenging Exploratory Research (No. 16K14447) from the Japan Society for the Promotion of Science (JSPS).
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