SINTESIS Y CARACTERIZACIÓN DE PELICULAS ULTRADELGADAS DE ÓXIDO DE HAFNIO IMPURIFICADO CON TERBIO

Abstract

In the present work, HfO2 ultrathin films were synthesized by the ultrasonic spray pyrolysis technique, from organometallic precursors and deposited on silicon, glass and quartz substrates. Different series of film deposition with three variable parameters: deposition temperature, deposition time and the concentration of the dopant were synthesized. The samples were characterized for the chemical composition analysis by X-ray Photoelectron Spectroscopy technique (XPS); the crystallographic structure was analyzed by X-ray diffraction; to determine the morphology and to measure the surface roughness we used atomic force microscopy (AFM) and; for the thickness determination profilometry and ellipsometry were used. The transparency of the sample in the visible region and the determination of the band gap energy were developed through UV-Vis spectroscopy and, photon and cathode luminescence were used for the analysis of their luminescent properties. The properties of the films were consistent with the expectations, showing: a thickness of 30 nm, the ability to emit visible light when they were irradiated with UV light, a low roughness when a temperature of 450 ºC was used for the synthesis, a high dielectric constant and, transparency in almost all the visible region of the electromagnetic spectrum when they were deposited at 450 ºC. It was found that the highest intensity of light emission was obtaining at 5% of Tb, emitting in the green color because its main emission is centered at 542 nm, originated from the electronic transition 4D47F5.