Tunable broadband upconversion luminescence from Yb3+/Mn2+ co-doped dual-phase glass ceramics

In comparison to narrow-band upconversion (UC) luminescence from lanthanide-doped systems, broadband UC emission enables a broad and tailorable emissive color, which is desirable for tunable lasers and multicolor display applications. Herein, dual continuous broadband UC emission covering the visible spectral region at 480–720 nm has been achieved for the first time in Yb 3+ /Mn 2+ co-doped glass ceramics (GCs) functionalized with the precipitation of dual-phase γ -Ga 2 O 3 / β -YF 3 nanocrystals . A tunable UC emissive color from yellowish to orange could be obtained under 980 nm excitation by varying the Mn 2+ doping content and heat treatment temperature of GCs. We ascribe this phenomenon to the typical transition of exchange-coupled Yb 3+ -Mn 2+ dimers in tetrahedral and octahedral ligand environments. The Stokes and power-dependent UC luminescence properties, fluorescence lifetimes, site occupation and the involved UC mechanism are discussed in detail. This research contributes to a better understanding of the UC process between Yb 3+ and Mn 2+ in transparent hosts and provides a novel perspective for designing broadband-emitting UC materials.