First-order and second-order infrared quantum cutting of Ho3+ Yb3+ doped oxyfluoride vitroceramics

Infrared quantum cutting is an international hot research field nowadays. Comparitive research between first-order and second-order quantum cutting of Ho3+ Yb3+ doped oxyfluoride vitroceramics is reported in present paper. It is found that most population can easily non-radiativly relax to (5F45S2) energy level when the energy levels between 5G5 and 5S2 are excited. For (5F45S2) level, the population of Ho3+ ion can be cross-transferred to 5I6 level by strong ETr7-ETaYb {5F4(Ho) 5I6 (Ho), 2F7/2(Yb) 2F5/2(Yb)} cross energy transfer passage; meanwhile, Yb3+ ion is excited to 2F5/2 level from 2F7/2 ground state. It results in the two infrared photons which can be absorbed by crystal Si, that is, one is (1153 nm, 1188 nm) infrared photon and the other is (973.0 nm, 1002.0 nm) infrared photon. Therefore, it results in two-photon first-order infrared quantum cutting. Finally, the cross energy transfer efficiency tr, 1%Yb(5F45S2)=29.2%, tr, 10.5%Yb(5F45S2)=99.2%. and cooperative energy transfer efficiency tr, 1%Yb(5F3)=4.18%, tr, 10.5%Yb(5F3)=75.3% of Ho(0.5)Yb(1):FOV and Ho(0.5)Yb(10.5):FOV are calculated. Their quantum efficiency up-limits of two-photon quantum cutting are CR, 1%Yb(5F45S2)=129.2%, CR, 10.5% Yb(5F45S2)=199.2 and CO, 1%Yb(5F3)=104.18%, CO, 10.5% Yb(5F3)=175.3% respectively. That is to say, the probability of first-order infrared quantum cutting is larger than that of second-order infrared quantum cutting. The present research is of significance for enhancing solar cell efficiency.