Realization of pure red emission from energy transfer in the Er3+–Tm3+ system under 1550 nm excitation

Abstract

NaY(WO4)2 is one of the excellent host materials for high-efficient upconversion luminescence, but it is still challenging to obtain red emission via lanthanide doping. In this work, pure red emission was achieved in the heavily-Er3+-doped NaY(WO4)2 by using a 1550 nm laser diode and introducing mediator Tm3+ ions in the lattice. On basis of the analysis of steady-state and transient-state luminescence properties related to dopant concentration and excitation wavelength, all possible red emission mechanisms were discussed. Finally, it has been demonstrated that the high-purity red emission was due to the several energy transfer processes between Er3+ and Tm3+. Our results provide a convenient pathway to investigate the upconversion luminescence mechanisms.