Advanced Materials: TechConnect Briefs 2016Advanced Materials TechConnect Briefs 2016

Nanoscale Materials Characterization Chapter 1

Infrared laser precipitation of ZnAl2O4 nanocrystals doped with Eu3+ and Yb3+ ions and efficient upconversion emission

C-H Bae, K-S Lim
Chungbuk National University, Korea

pp. 41 - 44

Keywords: glass ceramic, ZnAl2O4, nanocrystals, Er, Yb, CO2 laser

We present a novel and simple method to enable spatially selective ZnAl2O4 nanocrystal formation on the surface of glass. Zinc Aluminate, well-known as a wide band gap semiconductor, has been widely used as high temperature materials. Our approach to produce glass-ceramics does not require an electric furnace for thermal diffusion of composite materials in glass. It needs only a few minutes instead of several hours to precipitate nanocrystals in this study. We controlled CO2 laser power and scan speed to find optimized conditions for nanocrystal precipitation. We also found the down-shifting and up-conversion emissions of Eu3+ ions in glass-ceramics containing ZnAl2O4 nanocrystals are several times stronger than those in glass. Glass-ceramics was characterized by using micro-X-ray diffraction (-XRD), and tunneling electron microscopy (TEM) with EDS analysis techniques. The mean crystal size was 5 nm. We also report Yb3+ as efficient sensitizer for red photoemission from Eu3+ in glass ceramics under 980 nm excitation.