Carbonized Oligomer‐Like Dots: Efficient Persistent Room‐Temperature Phosphorescent Materials with Superior Mechanical Strength

Abstract The development of persistent room‐temperature phosphorescence (pRTP) materials has been rapid in recent years; however, producing pRTP materials with high luminescent characteristics, mechanical strength, and processability is a difficult issue. Herein, a new class of pRTP materials named carbonized oligomer‐like dots (CODs) is reported, which have injection molding capacity and high mechanical strength in castings. The luminescence and mechanical properties of the CODs (PN1‐PN4) may be altered by altering the quantity of phosphoric acid and diethylenetriamine using a microwave‐assisted heating technique. Among them, the longest lifetime of PN3 attains 1.21 s with an afterglow time of over 20 s, while the maximum Young's modulus of PN1 is up to 2.36 GPa. The existence of n–π* transition is beneficial to promote the intersystem crossing, and multiple hydrogen bonds in the aggregates play a crucial role in the formation of pRTP with mechanical and hot melt adhesive properties. This study may pave the way for the development of pRTP materials with superior mechanical strength in the fields of information encryption and flexible displays.