We report the effects of heterogeneous Yb 3+ and Er 3+ codoping in Y 2O 3 thin films on the 1535 nm luminescence. Yb 3+:Er 3+:Y 2O 3 thin films were deposited using sequential radical enhanced atomic layer deposition. The Yb 3+ energy transfer was investigated for indirect and direct excitation of the Yb 2+F 7/2 state using 488 nm and 976 nm sources, respectively, and the trends were described in terms of Forster and Dexters resonant energy transfer theory and a macroscopic rate equation formalism. The addition of 11 at. Yb resulted in an increase in the effective Er 3+ photoluminescence (PL) yield at 1535 nm by a factor of 14 and 42 under 488 nm and 976 nm excitations, respectively. As the Er 2O 3 local thickness was increased to greater than 1.1 Å, PL quenching occurred due to strong local Er 3+ ↔ Er 3+ excitation migration leading to impurity quenching centers. In contrast, an increase in the local Yb 2O 3 thickness generally resulted in an increase in the effective Er 3+ PL yield, except when the Er 2O 3 and Yb 2O 3 layers were separated by more than 2.3 Å or were adjacent, where weak Yb 3+ ↔Er 3+ coupling or strong Yb 3+ ↔ Yb 3+ interlayer migration occurred, respectively. Finally, it is suggested that enhanced luminescence at steady state was observed under 488 nm excitation as a result of Er 3+ → Yb 3+ energy back transfer coupled with strong Yb 3+ Yb 3+ energy migration.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)