Adjustable multi-color luminescence and energy transfer of capsule-shaped Gd2O2S: Tb3+, Sm3+ phosphors

Adjustable multi-color Gd 2 O 2 S: Tb 3+ , Sm 3+ phosphors were successfully prepared by solvothermal synthesis and calcination with sulfur. The phosphors have hexagonal crystal phase structure and good luminescence properties. The morphology of the sample is capsule-shaped and the size is uniform. Through the co-doped of activator ions (Tb 3+ , Sm 3+ ) and related characterization, it was proved that there was Tb 3+ to Sm 3+ energy transfer phenomenon in the Gd 2 O 2 S. The multilevel interaction is the main energy transfer mechanism of Tb 3+ and Sm 3+ proved by the critical distance. The Dexter multipole energy transfer theory and Reisfeld approximation theory are used to analyze the mode of multilevel interaction mechanism. The results show that the multilevel interaction mechanism is dipole-dipole interaction. The luminescence of Gd 2 O 2 S: Tb 3+ , Sm 3+ can be adjusted from green light to orange-red light by changing the concentration of doped ions and the excitation wavelength. The synthetic materials have certain significance in morphology control and luminescence regulation. • Based on the preparation of Gd 2 O 2 S sample, the co-doping of Tb 3+ and Sm 3+ ions was carried out, and finally the capsule-shaped phosphor with adjustable light color was obtained, which has excellent luminescence performance. • The energy transfer from Tb 3+ to Sm 3+ in Gd 2 O 2 S matrix was discovered. The mechanism and the interaction mode inside the sample were studied and demonstrated in details. • The adjustable luminescence of various colors from green to orange-red light can be achieved by changing excitation wavelength, doping concentration and the ratio of Tb 3+ and Sm 3+ .