Saimon, Jehan A., Mahdi, Rana O., Hadi, Aseel A., Khashan, Khawla S., Fadhil, Fattin A., Hadi, Iman H., and Bader, Ban A.
Al2O3 nanoparticles were created using laser ablation of an aluminum (Al) target in deionized water. The ablation process was carried out using three different laser fluences (12.7, 15.9, and 19.1 J/cm2). In this method, a 1064-nm Q-switched Nd:YAG laser with a 7-ns pulse width, 1-Hz repetition rate, and 100 pulses was used. The UV-visible absorption spectrum of the as-synthesized Al2O3 colloidal solution of nanoparticles showed an absorption maximum lying at 210 nm, which verified the presence of Al2O3 nanoparticles in deionized water. The bandgap of Al2O3 NPs decreased from 4.6 to 4.2 eV with the increased laser fluences. The fingerprint identification of Al2O3 colloidal nanoparticles was performed through FTIR spectroscopy analysis. The spectrum recorded several important stretch modes, including carbon, hydrogen, oxygen, and Al2O3 bands. Field emission scanning electron microscopy (SEM) was used to examine the morphology of Al2O3 nanoparticles produced at various laser fluences. It exposed the highly aggregated particles, which ranged in size from 91 nm to sub-micrometers. TEM images and size distribution of Al2O3 NPs showed that the partials size depended on laser fluence intensity. It showed that the majority of the nanoparticles produced by all of the ablated laser fluences have spherical shapes, with average particle sizes of 57, 70, and 117 nm at 12.7-, 15.9-, and 19.1-J/cm2 laser fluences, respectively. The effect of laser fluence on the photosensitivity of the Si detector based on the nanostructured Al2O3 film was studied. The photodetector showed strong responsiveness peaks at 350 and 800 nm, with values of about 1.2 AW−1 and 1.08 AW−1 corresponding to the responsiveness of the Al2O3 film and the Si substrate, respectively. It also displayed a high photo-detective value in the UV-Vis region. Therefore, nanosecond laser ablation in liquid is an efficient and adaptable approach for producing nanoparticles with customized size, shape, and properties. It is also a wonderful way to manufacture a variety of nanostructured materials that have applications in a variety of industries. [ABSTRACT FROM AUTHOR]