Highly efficient tunable white emission with ultralong afterglow in Sb3+/Mn2+-codoped CsCdCl3 crystals for multifunctional applications

Abstract

Recently, metal halides have attracted numerous attentions due to their fascinating optical properties. However, achieving efficient white emission with ultralong afterglow remains a great challenge. Herein, we reported Sb3+/Mn2+-codoped CsCdCl3 and the multiple emission bands can be observed, which derives from the self-trapped exciton emission of Sb-Cl moiety and the d-d transition of Mn2+. Thus, the tunable emission from cyan to orange light can be obtained, and moreover, efficient white emission with a luminous efficiency of 74% is witnessed when the energy-transfer efficiency from Sb3+ to Mn2+ is 34.5%. Particularly, Sb3+/Mn2+-codoped CsCdCl3 shows the bright orange afterglow emission, and the afterglow intensity is 1000 times that of CsCdCl3 and 20 times that of CsCdCl3:Mn2+, respectively. Combined with thermoluminescence spectra, it is found that Mn2+/Sb3+ codoping can effectively regulate the depth and density distribution of trap defects, resulting in the ultralong afterglow duration exceeding 12 hours at room temperature. Surprisingly, white light stimulation can provide additional photonic energy for Sb3+/Mn2+-codoped CsCdCl3, which enables the rapid release of trapped carriers to the emission center and rejuvenates afterglow emission after 12 hours pre-delay. Finally, we demonstrated the applications of as-synthesized compounds in single-component white light illumination, multiple optical anti-counterfeiting and information encryption.