Near-infrared-to-near-infrared down-shifting and upconversion luminescence of KY3F10 with single dopant of Nd3+ ion

We have studied the structural and near-infrared (NIR) luminescent properties of KY3F10 phosphors, singly doped with Nd3+ serving as both sensitizer and activator. With a single laser diode at the wavelength of 808 nm as a pump source, simultaneous NIR-to-NIR upconversion (UC) and down-shifting (DS) emissions are effectively achieved, due to the specific energy levels of Nd3+ dopant and the low phonon energy of the host. The luminescence mechanism related to energy transfer is discussed. The luminescence can be modulated through controlling the population of Nd3+:4F3/2 state in our experiment. Interestingly, both UC and DS emissions of the material fall within the dual biological window, suggesting that the prepared phosphors have potential applications in the bioimaging field.