Visible quantum cutting under excitations at 212 and 172nm in a green-emitting phosphor K2GdF5:Tb3+ (11%) via a downconversion mechanism is investigated. The authors measured the vacuum ultraviolet (VUV) excitation and emission spectra and proposed mechanisms to rationalize the quantum-cutting effect. One short-UV or one VUV photon absorbed by Tb3+ is split into multiple visible photons emitted by Tb3+ through cross relaxation and direct energy transfer. Calculations indicate an optimal quantum efficiency as great as 189% for this phosphor.
No takes yet. Share an insight, caveat, or question.
Lee et al. (2006) studied this question.
Synapse has enriched 2 closely related papers on similar clinical questions. Consider them for comparative context: