Temporal dynamics of upconversion luminescence in Er 3+, Yb 3+ co-doped crystalline KY(WO 4) 2 thin films

Abstract

Crystalline Er 3+ and Yb 3+ singly and doubly doped KY(WO 4) 2 thin films were grown by low-temperature liquid-phase epitaxy. Absorption, luminescence, excitation and temporal evolution measurements were carried out for both Er 3+ and Yb 3+ transitions from 10 K to room temperature. Green Er 3+ upconversion luminescence was observed after Yb 3+ and Er 3+ excitation. The mechanisms responsible for the upconversion phenomena detected in each case were identified.