Caracterización de películas luminiscentes de óxido de hafnio activadas con Eu$^{3 + }$ depositadas por la técnica de rocío pirolítico ultrasónico

Abstract

By means of the ultrasonic spray pyrolysis technique, trivalent europium doped hafnium oxide films were deposited. These films are amorphous at substrate temperatures lower than 350$^{\circ}$C, for higher substrate temperatures the films are polycrystalline presenting the HfO$_{2}$ monoclinic phase. The photoluminescence spectra for these films were studied as a function of the substrate temperature and the doping concentration. Samples excited with 395 nm radiation showed photoluminescence emission bands centered at 578, 591, 598, 612, 653 and 703 nm, associated to the electronic transitions of the trivalent europium. As the substrate temperatures are increased, an increment of the photoluminescence emission intensity was detected. Also, a concentration quenching of the photoluminescence intensity was observed. In addition, the chemical compositions of the deposited coatings and the characteristics of their surface morphologies are shown. The excitation band peaked at 395 nm, makes this material an excellent candidate for applications in solid state white lamps.