Visible red random lasing in Y₂O₃: Eu³⁺/ZnO polycrystalline thin films by energy transfer from ZnO films to Eu³⁺

Visible red random lasing centered at ∼611 nm has been observed in Y2 O3: Eu3+ /ZnO films at room temperature. Using a 355 nm laser source to excite the ZnO films, ultraviolet (UV) random lasing has been observed. The UV lasing spectrum can be tuned to overlap strongly with the F7 0 - L5 6 excitation spectrum of Eu3+ ions centered at ∼394 nm by controlling the pump power, leading to very efficient radiative energy transfer from the ZnO films to Eu3+ ions. As a result, a red random lasing centered at ∼611 nm corresponding to the D5 0 - F7 2 transition of Eu3+ ions was observed.