The photoluminescence and optoelectronics properties are very important for gallium nitride (GaN) nanoparticles in the applications of ultraviolet and blue optoelectronic devices. In this article, GaN nanoparticles are prepared and fabricated using femtosecond pulse laser ablation in liquid (PLAL). The X-ray diffraction results confirm that the synthesized GaN NPs are crystalline with a mixture of cubic and hexagonal phases, and the nanoparticles synthesized at 532 nm exhibit better crystallinity. The field emission electron microscope (FE-SEM) results demonstrate that the porous silicon consists of a high concentration of semicircular pores with an average diameter of the pore around 20 µm. Furthermore, the optoelectronic properties of the GaN/PSi are investigated to confirm its feasibility for double-junction photodetector and its applications. The outcomes show that the maximum responsivity was 3.8 A/W at 330 nm for a photodetector fabricated at 532 nm laser wavelength.
