Superbroad near-infrared photoluminescence from bismuth-doped CsPbI_3 perovskite nanocrystals

Bismuth-doped materials show fascinating near-infrared (NIR) photoluminescence (PL) properties. However, synthesizing Bi-doped, NIR-luminescent, nanometer-sized materials with high PL quantum yields remains challenging. Here, Bi-doped CsPbI3 perovskite nanocrystals (NCs) with an average size less than 10 nm and showing a superbroad NIR PL covering the telecommunication and second biological optical windows were achieved. The NIR PL quantum yield of these NCs is up to 7.17% with the Bi doping concentration of 0.074%. Additionally, efficient energy transfer from the semiconducting CsPbI3 to bismuth-related active center can be realized. We anticipate that the developed systems may find applications in optoelectronic and photonic devices as well as biological imaging. This work enriches the bank of Bi-doped luminescent materials, and might stimulate research interest for synthesizing other classes of Bi-activated nanomaterials.