Upconversion processes were studied in MeF2-ErF3 crystals (Me - Ca, Sr, Ba) in the range of ErF3 concentrations from 0.01 to 10 mol% when excited in infrared bands of the Er3 + ion by laser diodes of 808, 978, 1542 nm. Upon excitation of 1542 nm, the 4I11/2-4I15/2 band at 990 nm predominates in the luminescence spectrum of MeF2-Er; the fraction of visible bands is less than 0.1. The energy yield of the upconversion luminescence MeF2-10% ErF3 upon excitation of 1542 nm with a density of about 1 W/cm2 is in the range of 14-26%.
SrF2:Yb3+,Er3+ NPs were synthesized by the hydrothermal method and their luminescence mechanism was discussed in detail, which provided a theoretical basis for further understanding the properties of the materials.
Modulation of upconversion luminescence spectrum of single rare-earth-doped upconversion nanocrystal based on plasmonic nanocavity