Luminescence properties of chalcohalide devitrified glass containing BaCl2:Tm3+,Er3+ nanocrystals.

Pursuing low-phonon-energy (LPE) host for high luminescent efficiency of the doped active ions has stimulated the development of chalcohalide glass and the related nanocomposite via glass crystallization. In this work, a kind of chalcohalide devitrified glass (DG) containing BaCl 2 :Tm3+/Er3+ nanocrystals (NCs) were fabricated during glass melt-quenching. Interestingly, the DG yields some uncommon upconversion (UC) emission lines and enhanced UC/downshifted luminescence compared with the sample free of BaCl 2 , thanks to the partition of rare earth ions into the LPE environment of BaCl 2. There is an efficient energy transfer between Tm3+ and Er3+, whereupon Tm3+ doping enhances Er3+ 2.7 μm mid-infrared (MIR) emission by 1.85 times. Importantly, a distinctive viewpoint is proposed to understand the MIR enhancing mechanism, involving the reduction in cross relaxation (CR) processes among Er3+ ions via Tm3+ doping. • A new viewpoint for the enhanced Er3+ mid-infrared emission upon Tm3+ doping. • BaCl 2 nanocrystals precipitates from glass matrix during melt-quenching. • Rare earth ions partitioned into BaCl 2 nanocrystals with low phonon energy. • Some uncommon upconversion emission lines of Er3+ and Tm3+ are identified. [ABSTRACT FROM AUTHOR]