Luminescence upconversion mechanisms in Yb3+–Tb3+ systems

Surfactant effect on the upconversion emission and decay time of ZrO2:Yb-Er nanocrystals

“…Co-doping rare-earth ions with Yb increase the efficiency of the UPC process and in some cases can induce upconversion whereas it is not possible in the single ion. In this case, the emission is the result of energy transfer from donors to acceptors [4] such as Tm, Ho and Er [5,6]. Perhaps the most studied system is Yb-Er.…”

Tb3+-Yb3+ cooperative down and up conversion processes in Tb0.81Ca0.19F2.81:Yb3+ single crystals

“…This process has been proposed as a cooperative sensibilization one by Salley et al 20 Further, taking into account that Tb 3þ is a constituent in this matrix, it is reasonable to presume that this process can play a relevant role in our system. The evidence of this UC process is given in Fig.…”

Multicolor upconversion luminescence from RE3+-Yb3+ (RE=Er, Tm, Tb) codoped LaAlGe2O7 glasses

“…For LAGTb, the seven bands can be distinguished as the 5 D 3 → 7 F J (J = 2, 3, 4, 5, 6) and 5 D 4 → 7 F J (J = 3, 4, 5, 6) transitions of Tb 3+ as shown in Fig. 2(C) [24][25][26][27]. The relative intensities of the 5 D 3 → 7 F J transitions by infrared laser diode excitation are much weaker than by UV light; this is also caused by the inefficient excitation of 5 D 3 state.…”

“…For any process of UC luminescence, the visible output intensity I UC is approximately proportional to the nth power of infrared excitation intensity P IR [9,25]:…”