Tunable Energy Transfer from Dicyanoaurate(I) and Dicyanoargentate(I) Donor Ions to Terbium(III) Acceptor Ions in Pure Crystals

Abstract

A temperature-dependent photoluminescence study is reported for single crystals of M[Au(CN)2]3 and M[Ag(CN)2]3 (M = Tb; Gd; Y). The results indicate that in both Tb[Au(CN)2]3 and Tb[Ag(CN)2]3 exclusive excitation of the donor leads to sensitized luminescence for the acceptor, characteristic of the 5D4 → 7FJ (J = 0−6) transition of Tb(III). However, the sensitized luminescence is much stronger in Tb[Ag(CN)2]3 than in Tb[Au(CN)2]3 due to a larger spectral overlap between the [Ag(CN)2-] emission and the Tb(III) absorption. Upon increasing the temperature, energy transfer is enhanced in Tb[Ag(CN)2]3 but inhibited in Tb[Au(CN)2]3. In Tb[Ag(CN)2]3, a large spectral overlap exists between the [Ag(CN)2-] donor emission and the Tb(III) acceptor absorption at all temperatures. The Tb(III) sensitized emission is strong at all temperatures and is enhanced upon a temperature increase while the [Ag(CN)2-] emission is quenched. An activation energy of 53.7 cm-1 (±2.5 cm-1) has been calculated for the energy transfer pro...