Tuning broadband up-conversion by precipitation of perovskite KMgF3 nanocrystals in fluorosilicate glasses

Abstract

Co-doping of Yb3+ with Mn2+ is a promising way to realize broadband up-conversion (UC) luminescence. The tunable broadband emission has been widely demonstrated in crystal materials, but the research on Yb3+/Mn2+ co-doped transparent optical glass has been scare, especially in fluoride-based transparent glass ceramics (GC) that can realize the uniform ions incorporation and efficient UC emission. Herein, a series of Yb3+/Mn2+ activated transparent fluorosilicate GCs containing perovskite KMgF3 nanocrystals were successfully prepared, and the effect of heat-treatment process and/or Mn2+ ion content on the UC luminescence modulation has been investigated. Our results show that the spontaneous crystallized precursor sample exhibits only a green emission at ~538 nm, while additional orange-emitting band centered at ~613 nm is noticeable in the GCs with the gradual precipitation of KMgF3 nanocrystals after heat-treatment. The controllable luminescence can be assigned to the formation of Yb3+-Mn2+ dimers that are located in multiple coordination environments provided by the glass matrix and crystalized nanocrystals. In addition, the prepared GC samples exhibit excellent reversible emission characteristics during heating and cooling cycles. This research not only provides a new option to design desirable coordination environment for Yb3+-Mn2+ dimers, also helps to recognize the UC process in the transparent matrix in detail.