Abstract
AbstractTb3+/Yb3+ co‐doped Na5Lu9F32 single crystals with ≈1.0 mol% Tb3+ concentrations and various Yb3+ are prepared by Bridgman method. Several visible up‐conversion (UC) luminescence are observed following the excitation of 980 nm laser diode (LD) as well as its pump power dependence on UC emission of the crystals. The quadratic dependence of pump power on UC emission reveals that two‐photon UC processes are mainly responsible for the 486 nm and 543 nm emissions of Tb3+/Yb3+ co‐doped system in Na5Lu9F32 single crystals. It is proposed that cooperative energy transfer (CET) from two excited Yb3+ ions to the ground state of Tb3+ ions is in charge of the ≈486 nm, ≈543 nm and ≈620 nm, which are attributing to 5D4 → 7F6, 5D4 → 7F4 and 5D4 → 7F3, respectively, are obtained in Tb3+/Yb3+ doped Na5Lu9F32 single crystals. Furthermore, a favorable yellowish green light performance can be achieved with certain Yb3+ concentrations and 1.0 mol% Tb3+ co‐doped samples, and its external quantum efficiency approached to 1.25% under 5.5 W cm−2 980 nm excitation which makes further research valuable in developing processable UC materials for electro‐optical devices.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
