Ultra-long room temperature phosphorescence of indium-based organic inorganic metal halides for naked-eye-visible afterglow

Solid-state molecules based on room-temperature phosphorescent (RTP) emission have received extensive attention due to their special optical properties of triplet excitons. However, there are still few solid molecular systems with naked-eye-visible afterglow characteristics. Herein, we introduce 4-phenylbenzylamine (namely PBA) with a long conjugated system into common non-toxic In 3+ to form an indium-based organic inorganic halide, whose chemical formula is PBA 3 [InCl 6 ]·H 2 O. Interestingly, this hybrid halide generates a RTP emission at 617 nm with a lifetime decay as long as 290.4 ms, expressing a naked-eye-visible afterglow for more than 7 s. The mechanism study shows that the long lifetime RTP originated from the specific lamellar stacking of organic molecules and metal halide units, facilitating the interaction between the inorganic layers and organic layers. Therefore, the material can be potentially used in emergency lighting, information security, and other fields. Meanwhile, this work provides a reference for the design and implementation of a more efficient organic-inorganic hybrid system with the ultralong RTP emission.