Laser induced broadband Vis and NIR emission from Yb:YAG nanopowders

The laser induced broadband emission (LIBE) of (YbxY1-x)(3)Al5O12 nanocrystals was investigated in vacuum using the focused infrared laser beam. The samples were prepared via Pechini's technique. The different shapes of LIBE spectra were observed. The LIBE characteristics including an order of the process, rise and decay times, were independent on the type of emission spectra and concentration of Yb3+ ions. Intensity of the emission spectra decreased increased with time after switching off/on the laser excitation, while the shape of the emission spectra remained approximately the same. This is consistent with the colour of the emission, which remains white even after significant decrease in intensity. For the first time, the generation of broadband emission begins after reaching a certain time threshold in range 0-10 s, and disappearing afterwards. Beforehand, several possible LIBE mechanisms have been proposed for different materials, however they don't cover all aspects of this phenomenon. In the present article, the intervalence charge transfer (IVCT) model is considered as general for RE doped phosphors. The features of LIBE have been described within this model. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The laser-induced broadband emission of (YbxY1-x)(3)Al5O12 nanocrystals was investigated in vacuum using focused infrared laser beam. Different shapes of emission spectra were observed, with intensity decreasing over time but the shape remaining consistent, and broadband emission appearing within a certain time threshold before disappearing. These characteristics were described within the framework of the intervalence charge transfer (IVCT) model for RE doped phosphors.