In this work, we have investigated the near-infrared (NIR) photoluminescence, upconversion (UC), and long-lasting phosphorescence properties of Nd3+/Yb3+-doped Ca2SnO4 phosphors. Two-photon NIR quantum cutting (QC) luminescence is observed when the Nd3+-O2- charge-transfer band in Ca2SnO4:Nd3+, Yb3+ phosphors was excited, and the theoretical quantum yield is found to be close to 200%. More interestingly, the unique two-photon UC red emission under 808 nm laser diode excitation and NIR QC persistent luminescence can be realized only in Nd3+-Yb3+ codoped samples. The energy-transfer mechanism between Nd3+ and Yb3+ is revealed from the energy level structure and decay measurements. Different cross-relaxation schemes related to 2F5/2-2F7/2 of Yb3+ and f-f transition of Nd3+ are proposed. The results show that multifunctional luminescence properties are achieved in Nd3+-doped Ca2SnO4 with the introduction of Yb3+.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films