Synthesized of gallium Nitride/PSi nano thin films using 532 nm wavelength by pulsed laser deposition technique

• Published in: Engineering and Technology Journal Vol. 42; no. 10; pp. 1242 - 1254
• Main Authors: Abeer Abbas, Ali Alwahib, Makram Fakhri, Subash C. B. Gopinath, U. Hashim
• Format: Journal Article
• Language: English
• Published: Unviversity of Technology- Iraq 01-10-2024
• Subjects: gan; nanostructure; psi; pulsed laser deposition; thin films
• ISSN: 1681-6900; 2412-0758
• DOI: 10.30684/etj.2024.145816.1667

The porous silicon (PSi) substrate was accurately synthesized using photoelectrochemical etching. A Nanofilm gallium nitride (GaN) was then precisely deposited on this PSi substrate using pulsed laser deposition (PLD). The x-ray diffraction (XRD) investigation revealed the GaN layer's distinct crystalline structure along the (002) plane, with a precise crystallite size of 21.57 nm. This precision in the deposition process enhanced both the surface morphology and film quality. In the atomic force microscope (AFM), oval particles were evenly distributed across the entire surface, and the RMS of the surface was 27 nm with a 20.63 nm surface roughness. A field emission scanning microscope (FESEM) image of the gallium nitride (GaN) films deposited at a wavelength of 532 nm showed that the GaN material had an evenly covered Psi surface. This reflected the presence of a smooth and even spread of round particles. The cross-sectional area of the GaN sheet had a thickness of 2.92 µm, demonstrating the precision of the deposition technique. The resulting GaN nanofilms demonstrate UV photoluminescence (P.L.), characterized by a wavelength peak of 363.7 nanometers, indicative of the GaN material. In addition, they display a red photoluminescence peak at 723 nanometers, corresponding to the PSi substrate. Under UV-visible light and photoluminescence (P.L.), the optical energy gaps of the GaN nanofilm and the PSi substrate were determined. The PSi substrate exhibited an optical energy gap of 2.1 electron volts, whereas the resulting gallium nitride nanofilms displayed multiple energy band gaps of 3.4 electron volts and 1.7 electron volts.