Tunable Emission of Pb(II) and Sb(III) Codoped 2D Hybrid BDACdBr<sub>4</sub> Metal Halides for Cryptographic Anticounterfeiting Applications
Jiacong Liao, Canxu Chen, Yunlong Bai, Jiandong Yao, Bingsuo Zou, Ruosheng Zeng
Abstract
Organic–inorganic hybrid metal halides have attracted much attention due to their remarkable optoelectronic properties. However, two-dimensional (2D) hybrid BDACdBr 4 (BDA is 1,4-butanediamine) metal halides exhibit poor luminescence due to the indirect band gap nature. Herein, we successfully prepared Pb 2+ - and Sb 3+ -codoped BDACdBr 4 single crystals through a recrystallization method, resulting in a tunable emission color. Under ultraviolet light excitation, the emission color switched from cold white, white, and warm white to orange-red, resulting from the different color ratio of the intrinsic self-trapped exciton emission of Pb 2+ and Sb 3+ ions with an ns 2 electron configuration. The photoluminescence decay demonstrated efficient energy transfer from the Pb 2+ to Sb 3+ ions with an increasing ratio of Sb 3+ /Pb 2+ doping. Based on the tunable emission under 365/395 nm excitations, this material exhibits promising cryptographic anticounterfeiting application. This work provided a reference for tuning the optical performance of Cd-based metal halides through a metal ion-codoping strategy.