Photoluminescence, cathodoluminescence degradation and surface analysis of Gd2O3:Bi pulsed laser deposition thin films

Abstract

Gd2-xO3:Bix = 0.003 thin films were successfully deposited on Si (100) substrates in vacuum and an oxygen atmosphere at different substrate temperatures using the pulsed laser deposition technique. The microstructure, surface topography, chemical composition analysis and luminescent properties of the samples were studied. The influence of prolonged electron beam exposure on the surface state, chemical and cathodoluminescence (CL) stability of the samples was investigated. The background atmosphere and substrate temperature were found to significantly affect the microstructure and photoluminescence (PL). According to scanning electron microscopy cross-sections, the thicknesses for the thin films were relatively constant around 100 nm. The CL emission intensity degradations in a vacuum and an oxygen atmosphere were checked synchronously with the Auger peak-to-peak heights using the same electron beam for both measurements. The effect of the electron bombardment on the surface state of the samples was studied by using Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). All major elements (gadolinium and oxygen) were located, with additional carbon and chlorine that were removed during the early stages of electron bombardment. Generally, the CL intensity of the thin films with a blue-green emission was stable under electron bombardment, indicating that this phosphor may be appropriate for field emission displays applications.