Nonradiative Energy Transfer in Bi2O3/Tm2O3 Powders under IR Excitation at Liquid Nitrogen Temperature

The presented work shows the study of energy transitions in the NIR and visible regions in the system of Bi2O3 and Tm2O3 powders. Mechanisms of upconversion luminescence and NIR luminescence between two Bi3+ and Tm3+ ions at T = 80 K accompanied with nonradiative energy transfer through the vibrational levels were investigated under IR photoexcitation. The absorption bands of the samples on the reflection spectra were examined in the visible region. The values of the emission cross-section parameters were calculated for the Bi2O3/Tm2O3 complexes.