All-Inorganic Cs2YbCl5·H2O Perovskite with Luminescence Response to Methanol for Anti-Counterfeiting

Stimuli-responsive luminescent materials have attracted much research attention due to their wide application potential in various fields. Typically, the family of hydrated double perovskite A 2 M III X 5 ·H 2 O shows unique emission color transformation between hydrated and dehydrated complexes, highlighting the application potential in advanced anti-counterfeiting. Herein, two zero-dimensional perovskites of Cs 2 YbCl 5 ·H 2 O and Cs 3 YbCl 6 , are reported and broad-band self-trapped exciton recombination emission can be realized via external Sb 3+ doping. Intriguingly, the Cs 2 YbCl 5 ·H 2 O can be transformed to the dehydrated counterpart of Cs 3 YbCl 6 through a facile methanol treatment at room temperature, leading to the emission color transformation from yellow to green. Notably, the green-emissive Cs 3 YbCl 6 :Sb 3+ delivers a high photoluminescence quantum yield of 67.3%. Leveraging the advantages of obvious methanol-induced emission color transformation between Cs 2 YbCl 5 ·H 2 O and Cs 3 YbCl 6 at room temperature, Cs 2 YbCl 5 ·H 2 O can be used in the field of high-security-level anti-counterfeiting.