Long Persistent Luminescence from All‐Inorganic Perovskite Nanocrystals

The advantages of ultrahigh quantum yield and narrow spectral bandwidth of all-inorganic lead halide perovskite (NCs) enable them as the most potential candidates for optoelectronic applications. However, it is difficult to obtain long persistent luminescence from inorganic perovskite as the creation of effective trapping centers comes along with the generation of nonradioactive recombination centers. Here, replacing Pb(2+)by appropriate lanthanide ions (Ln(3+)) in CsPbBr(3)that are embedded inside an amorphous transparent medium via a high-temperature (approximate to 500 degrees C) fabrication process is proposed to achieve stable and effective trapping centers. Furthermore, the surface coating of the enclosed prevents the formation of surface defects, leading to long persistent luminescence from CsPbBr3: Ln(3+)NCs. The CsPbBr3: Ln(3+)NCs with unprecedented high color purity (approximate to 89.9%) and long lasting time of more than 1800 s could be a promising candidate for the application in anti-counterfeiting.