Energy transfer mechanisms of quantum cutting near infrared luminescence in Ho3Â +/Yb3Â + co-doped Y2O3 transparent ceramics

Blue to near infrared quantum cutting luminescence has been achieved in the Ho3 +/Yb3 + co-doped Y2O3 transparent ceramics upon the 449 nm excitation. Based on the steady and the dynamic emission spectra and the energy level diagrams of Ho3 + and Yb3 +, the energy transfer between Ho3 + and Yb3 + was proposed to be first via the Ho3 +: 5 F4, 5S2 + Yb3 +: 2 F7/2 → Ho3 +: 5I6 + Yb3 +: 2 F5/2 cross relaxation, then followed by the efficient energy transfer from Yb3 +: 2 F5/2 to Ho3 +: 5I6, and further the enhanced Ho3 +: 5I6 → 5I8 transition emitting at 1206 nm.