Eu3+ photoluminescence enhancement due to thermal energy transfer in Eu2O3-doped SiO2-B2O3-PbO2 glasses system

In this work, Eu3+-doped lead borosilicate glasses (SiO2-B2O3-PbO2) synthesized by fusion method had their optical properties investigated as a function of temperature. Atomic Force Microscopy images obtained for a glass matrix annealed at 350 and 500 degrees C show a precipitated crystalline phase with sizes 11 and 21 nm, respectively. Besides, as the temperature increases from 350 to 300 K a strong Eu3+ photoluminescence (PL) enhancement takes place. This anomalous feature is attributed to the thermally activated carrier transfer process from nanocrystals and charged intrinsic defects states to Eu3+ energy levels. In addition, the PL peaks in this temperature range were assigned to the Eu3+ transitions D-5(0)-> F-7(2), at 612 nm, D-5(0)-> F-7(1), at 595 nm, and D-5(0)-> F-7(0), at 585 nm. It was also observed that the D-5(0)-> F-7(3) and D-5(0)-> F-7(4) PL bands at 655 and 700 nm, respectively, show a continuous decrease in intensity as the temperature increases. (C) 2010 Elsevier B.V. All rights reserved.