Upconversion luminescence of CaF2-SrF2-ErF3 single crystals upon 1.5 μm laser excitation

Abstract In present work, the spectral-luminescent properties of CaF 2 -SrF 2 -ErF 3 (CaF 2 -SrF 2 :Er) single crystals were investigated. The upconversion luminescence (UCL) of CaF 2 -SrF 2 : Er in the visible and infrared spectral regions upon excitation of the 4 I 13/2 level Er 3+ ions were studied for the first time. The absolute energy yields of the UCL upon laser excitation at 1.5 μm are determined for CaF 2 -SrF 2 :Er. The possible application of fluoride crystals for increasing the efficiency of solar cells was discussed.