Host-to-activator energy transfer in a new blue-emitting phosphor SrHfO3 : Tm3+

A new phosphor, SrHfO3:Tm3+, shows a blue luminescence of high color purity with a peak at 457 nm originated from P-3(0) state. Below the fundamental absorption edge at around 200 nm, an excitation band presumably due to a charge transfer state (CTS) of Tm3+ is observed. This situation allows efficient energy transfer from the host to Tm3+ via the CTS, providing a relatively high-energy efficiency of Tm3+ luminescence in oxides, which is about 4% under 25 kV electron-beam excitation. (C) 2000 Elsevier Science B.V. All rights reserved.