<p>GaN nanostructures have been formed by utilizing both pulsed laser ablation in liquid (PLAL) and the hydrothermal method to create nanostructures. The use of three different energy levels of pulsed laser (100, 200, and 300 mJ) allowed researchers to measure the impact of the changing energy on the structural, morphological, optical, chemical, and electrical properties of the final product. This was done through a variety of different means of measuring these connections. Comparing both colloidal GaN and those films grown on hydrothermally treated substrates, it was found that crystallinity and overall quality of the final material had been improved considerably with the use of the laser. This revealed that the use of the laser for the growth of crystals is critical. Optical measurements showed an increase in the energy band gap 3.05–3.18 eV for colloidal and 3.22–3.55 eV for hydrothermally deposited thin film. FESEM analysis demonstrated improved morphology and uniformity due to the high-temperature and high-pressure conditions of the hydrothermal process. XRD patterns revealed distinct peaks at 2<i>θ</i> = 34.85°, 38.35°, and 59.15°, corresponding to the (002), (100), and (200) planes, respectively, confirming the hexagonal wurtzite structure of GaN. Electrical characterization showed decreased resistivity with increased reaction temperature. Based on optimal performance from the figure of merit, a photodetector was fabricated by depositing GaN films onto n-type and p-type Si substrates. The GaN/n-Si device exhibited superior electrical performance compared to GaN/p-Si, with an ideality factor of 1.6. The photodetector demonstrated high stability. The (GaN /n-Si) detector showed the highest response at short wavelengths (UV region), with a response of 0.025 AW at 320 nm. The GaN /p-Si detector also showed good responsivity at 320 nm. However, it was lower, reaching 0.020 AW, and had high detectivity, confirming its potential for optoelectronic applications.</p>