Sensitisation of the luminescence of Er3+ and Ho3+ ions by Cr4+ ions in a Y2SiO5 crystal

Abstract

The luminescence of Er3+ and Ho3+ ions was sensitised by Cr4+ ions in an yttrium orthosilicate Y2SiO5 (YSO) crystal. The luminescence spectra of YSO : Cr : Er and YSO : Cr : Ho crystals and the kinetics of the luminescence of the Cr donor ions were investigated at 77 K and 300 K and analysed. Radiative energy transfer from Cr4+ to Ho3+ was observed in a Y2SiO5: 0.2% Cr : 0.5% Ho crystal. The Cr4+—Er3+ energy transfer in a Y2SiO5 : 0.1% Cr : 1.3% Er crystal at 77 K involved a nonradiative dipole—dipole static mechanism in the interval 2.7–24 μs. The efficiency of nonradiative energy transfer from Cr4+ to Er3+ was estimated to be 14%—19% at 77 K.