Lanthanide/Bismuth-Codoped Lead-Free Halide Double Perovskite Nanocrystals with Upconversion and Short-Wave Infrared Luminescence

Lead-free halide double perovskite (DP) nanocrystals (NCs) have been regarded as a class of environmentally friendly and promising optoelectronic nanomaterials. Herein, we report the synthesis and luminescence properties of all-inorganic lanthanide/bismuth (Ln3+/Bi3+)-codoped Cs2NaInCl6 DP NCs. Yb/Er-codoped Cs2NaInCl6 NCs show upconversion (UC) and downshifting short-wave infrared (SWIR) photoluminescence (PL). By further introducing Bi3+ ions into the host, both UC and SWIR PL can be significantly enhanced, which are 2 orders of magnitude higher than those of Bi-free DP NCs. This is mainly due to the excellent synergy between the lanthanide and bismuth dopants and the high compatibility of these dopants with the Cs2NaInCl6 host. This work will help to guide the design and development of novel highly efficient luminescent nanomaterials.