Electronic structure and photoluminescence properties of Zn-ion implanted silica glass before and after thermal annealing

Abstract

The results of XPS core-level and valence band measurements, photoluminescence spectra of a-SiO2 implanted by Zn-ions (E = 30 key, D = 1 . 10(17) cm(-2)) and Density Functional Theory calculations of electronic structure as well as formation energies of structural defects in silica glass induced by Zn-ion implantation are presented. Both theory and experiment show that it is energetically more favorable for implanted zinc ions to occupy the interstitial positions instead of cation substitution. As a result, the Zn-ions embedded to interstitials, form chemical bonds with the surrounding oxygen atoms, fabrication ZnO-like nanoparticles and oxygen-deficient SiOx matrix. The subsequent thermal annealing at 900 degrees C (1 h) strongly reduces the amount of ZnO nanoparticles and induces the formation of secondary alpha-Zn2SiO4 phase which markedly enhances the green emission. (C) 2015 Published by Elsevier B.V.