Efficient near-infrared emission in Eu3+-Yb3+-Y3+ tri-doped cubic ZrO2 via down-conversion for silicon solar cells

Eu3+-Yb3+-Y3+ tri-doped cubic ZrO2 (abbreviated as YSZ:Eu,Yb) phosphors with different doping concentrations of Yb3+ can be synthesized via the Pechini sol-gel method. Efficient near-infrared (NIR) emission in YSZ:Eu,Yb phosphors was demonstrated. The dependence of the intensities of visible and NIR emissions, decay lifetimes and energy-transfer efficiencies on the Yb3+ doping concentration was investigated in detail. It is found that Eu3+, acting as a sensitizer, can efficiently transfer its energy to Yb3+ activator ions in YSZ:Eu,Yb phosphors.