Introducing and studying origin of deep electron traps in Ba1-xZrSi3O9:xEu for optical data storage

Abstract

Eu ions doped Ba 1-x ZrSi 3 O 9 :xEu materials are synthesized by solid state reaction method, facing optical data storage applications. The doping of Eu ions introduces deep electron traps at 0.90 eV below the conduction band minimum of Ba 1-x ZrSi 3 O 9 :xEu (1400 °C air). Moreover, the trap distribution is tunable, and there are only deep traps in sample Ba 0·85 ZrSi 3 O 9 :0.15Eu (1400 °C Ar/H 2 ) with the disappearance of shallow traps. Deep traps can prevent information from loss, while the disappearance of shallow traps can eliminate interference to deep traps by avoiding redeployment of electrons between shallow and deep traps over time. Further, post-sintering in a reducing atmosphere after sintering in the air can increase the concentration of deep traps and deepen the color of samples, while post-sintering in the air after sintering in a reducing atmosphere can obviously decrease the concentration of deep traps and the color of samples return to white from yellow. Experimental results indicate that the deep traps in samples Ba 1-x ZrSi 3 O 9 :xEu should originate from oxygen vacancy defects, which also serve as color centers. First principles calculations show that V O1 oxygen vacancy defects introduce obvious defect energy levels below the conduction band minimum of BaZrSi 3 O 9 -V O1 , which further illustrate the deep traps should originate from V O1 oxygen vacancy defects located at the connection of layer to layer in layered matrix. Ba 1-x ZrSi 3 O 9 :xEu materials with deep electron traps are good candidates for optical data storage. • The doping of Eu ions introduces deep electron traps. • The trap distribution is tunable by atmosphere treatment. • The deep traps should originate from V O1 oxygen vacancy. • Ba 1-x ZrSi 3 O 9 :xEu materials are good candidates for optical data storage.