A study on the field emission properties of Bi2Se3 nanostructures prepared by laser ablation

Abstract

One of the effective methods known as pulse laser ablation in liquid (PLAL), in which a solid target material is immersed in an organic solvent and laser beam is irradiated through liquid on a target material, is a direct method used to generate nanoparticles in liquid medium. The present work is focused on the preparation of bismuth selenide (Bi2Se3) nanoparticles using PLAL to study their field emission characteristics. The PLAL was performed under nanosecond (ns) laser with different ablation time of 120 min and 240 min. The field emission characteristics were measured in the planer “diode” configuration in all metal ultra-high vacuum (UHV) chamber. The prepared Bi2Se3 nanoparticles were analyzed with different characterization techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD) and UV-visible spectroscopy in order to study the surface morphology and structural information. The generation of Bi2Se3 nanoparticles is found after PLAL, which clearly suggests that bulk Bi2Se3 microsheet is transformed into Bi2Se3 nanoparticles. The X-ray spectra and UV spectra show the formation of nanoparticles upon laser ablation. The improvement in the field emission properties is found for laser-ablated Bi2Se3 nanoparticles. The field emission characteristics lead to increase in current density, which can be ascribed to the reduction in size of Bi2Se3 nanoparticles due to laser ablation. The prepared Bi2Se3 nanoparticles could be considered for novel applications in optoelectronics devices.