Stepwise Unlock Full‐Spectrum Emission with Abnormal Anti‐Thermal Quenching in Indium‐Based Metal Halides by Tailoring Their Crystal Structure Engineering
Xiaokang Li, Hui Peng, Ou Xu, Wenjie Huang, Linghang Kong, Qilin Wei, Zhentao Du, Wenchao Yang, Bingsuo Zou
Abstract
Abstract Lead‐free metal halides with tunable optical properties have emerged as a class of optoelectronic materials with great application potential. The optical properties of metal halides are closely related to their crystal structures, and the diversity of crystal structures is a key factor in achieving efficient tunable emission. Herein, four different Sb 3+ ‐doped In 3+ ‐based metal halides of 3D Cs 2 KInCl 6 :Sb 3+ , 1D (DFEA) 2 KInCl 6 :Sb 3+ and (DFEA) 2 (NH 4 )InCl 6 :Sb 3+ , and 0D (DFEA) 3 InCl 6 :Sb 3+ (DFEA = 2, 2‐difluoroethylamine) are reported, all of which exhibit different crystal structures, resulting in efficient tunable emission bands shift from 495 to 605 nm. It is found that the larger [SbCl 6 ] 3− distortion is the reason for the redshift of the emission band, which allows to stepwise unlock the full‐spectrum emission with ultra‐high luminescence efficiency. Compared all‐inorganic Cs 2 KInCl 6 :Sb 3+ , the other three Sb 3+ ‐doped hybrid In 3+ ‐based metal halides exhibit abnormal anti‐thermal quenching behavior, which should be attributed to the participation of shallow trapped states caused by the structural defects. The tunable emission characteristics of Sb 3+ ‐doped metal halides make them show great application potential in solid‐state lighting, optical anti‐counterfeiting, and information encryption.