Visible Quantum Cutting in LiGdF 4 :Eu 3+ Through Downconversion

Abstract

For mercury-free fluorescent lamps and plasma display panels, alternative luminescent materials are required for the efficient conversion of vacuum ultraviolet radiation to visible light. Quantum cutting involving the emission of two visible photons for each vacuum ultraviolet photon absorbed is demonstrated in Eu 3+ -doped LiGdF 4 with the concept of downconversion. Upon excitation of Gd 3+ with a high-energy photon, two visible photons can be emitted by Eu 3+ through an efficient two-step energy transfer from Gd 3+ to Eu 3+ , with a quantum efficiency that approaches 200 percent.