Near-infrared quantum cutting in Ho(3+), Yb(3+)-codoped BaGdF(5) nanoparticles via first- and second-order energy transfers

Infrared quantum cutting involving Yb(3+) 950–1,000 nm ((2) F(5/2) → (2) F(7/2)) and Ho(3+) 1,007 nm ((5)S(2),(5)F(4) → (5)I(6)) as well as 1,180 nm ((5)I(6) → (5)I(8)) emissions is achieved in BaGdF(5): Ho(3+), Yb(3+) nanoparticles which are synthesized by a facile hydrothermal route. The mechanisms through first- and second-order energy transfers were analyzed by the dependence of Yb(3+) doping concentration on the visible and infrared emissions, decay lifetime curves of the (5) F(5) → (5)I(8), (5)S(2)/(5)F(4) → (5)I(8), and (5) F(3) → (5)I(8) of Ho(3+), in which a back energy transfer from Yb(3+) to Ho(3+) is first proposed to interpret the spectral characteristics. A modified calculation equation for quantum efficiency of Yb(3+)-Ho(3+) couple by exciting at 450 nm was presented according to the quantum cutting mechanism. Overall, the excellent luminescence properties of BaGdF(5): Ho(3+), Yb(3+) near-infrared quantum cutting nanoparticles could explore an interesting approach to maximize the performance of solar cells.