Color‐tunable and white emission of Tm3+ doped transparent zinc silicate glass‐ceramics embedding ZnO nanocrystals

Abstract

AbstractTm3+ doped zinc silicate glass‐ceramics composed of SiO2‐Al2O3‐ZnO‐K2O‐Tm2O3 embedded with ZnO nanocrystals were successfully fabricated by melt‐quenching method with subsequent heat treatment. Tm3+ ions and ZnO nanocrystals were introduced as blue and yellow luminescence centers, respectively. The effects of heat treatment, excitation wavelength and Tm3+ doping concentration on the photoluminescence behaviors of these glass‐ceramics were studied. Short‐time (5 minutes) heat treatment was considered as the optimal heat treatment time, which facilitates simultaneously emitting narrow blue peak located at 453 nm and a broad yellow band centered at 580 nm. Blue and yellow emissions could be attributed to the 1D2 → 3F4 transition of Tm3+ and Zni/Oi‐related defect emission of ZnO nanocrystals, respectively. The combination of these two emissions allows the realization of white light emitting in the glass‐ceramic samples. Furthermore, tunable luminescent color and chromaticity coordinates, including yellow, white and blue, can be realized by varying the pumping wavelengths as well as the content of Tm3+ dopant in the glass matrix. Nearly perfect white light emission with Commission Internationale de l'Eclairage coordinate (x = 0.33, y = 0.32) was achieved for the 0.05 mol% Tm3+ doped glass‐ceramic embedding ZnO nanocrystals by heat treatment at 750°C for 5 minutes under the excitation of 360 nm. These luminescent glass‐ceramics doped with Tm3+ ion and ZnO nanocrystals could be a promising candidate for white light emitting devices under near‐ultraviolet excitation.