The influence of deposition gases on the material properties of Y2SiO5: Ce3+ thin films deposited by pulsed laser deposition (PLD) method

Abstract

The material properties of Y _2 SiO _5 : Ce ^3+ thin films have been investigated. The X-ray powder diffraction (XRD) analysis shows that the films are structurally monoclinic with the most prominent diffraction peak of 15.7 °. The maximum crystallize size was obtained for samples deposited under oxygen deposition. The PL emission peaks are observed at 423 nm when probed at 370 nm, which can be ascribed to the transition of the electrons from the excited state of 5d to the ground state of 4f. Due to the spin–orbit interactions, the 4f ground state splits into ^2 f _5/2 and ^2 f _7/2 energy sub-levels. The scanning electron microscopy (SEM) measurement shows a rough and uniform distribution of grains with small agglomerated topographic areas. The energy dispersive spectroscopy (EDS) measurements shows the presence of all elements (Y, Si, O, and Ce). The maximum and minimum absorbance of the visible ultraviolet (UV–vis) spectrum was observed for the thin films deposited under the Argon and vacuum atmospheres with small shifts from Argon to the other depositions. The energy bandgap varies between 3.14 and 4.33 eV. The CIE measurement gives the blue emission band at an emission wavelength of 423 nm. The activation energy was obtained in the range of 0.1733 and 0.1938 eV. The maximum activation energy was obtained under the argon gas deposition.

Keywords

• rare earth compounds
• yttrium silicate
• phosphors
• thermoluminescence
• pulsed laser deposition
• deposition gases