Lattice Distortion Promoting Wavelength‐Tunable Emissions in Cu(I)‐Based Halides for Thermography and Anti‐Counterfeiting
Kai Han, Shuai Zhang, Jiance Jin, Yongsheng Sun, Yuzhen Wang, Zhiguo Xia
Abstract
Abstract Low dimensional hybrid metal halides as a chemically tunable platform achieve multi‐functional optical applications with versatile luminescence mechanisms. Herein, we design and prepare Cu(I)‐based hybrid halide (DMAP)Cu 3 I 4 (DMAP = 4‐Dimethylaminopyridine), with ambient temperature‐induced photoluminescence evolution from red to near‐infrared emissions. The in situ variable‐temperature crystallographic study reveals lattice distortion with more disordered [Cu 3n I 4n ] n− units appear at high temperature, further indicating that the observed wavelength‐tunable emission is attributed to transitions from Cu cluster center to halogen‐to‐metal charge transfer. Thus, (DMAP)Cu 3 I 4 shows a compelling thermometric precision (high sensitivities of 0.0001–0.6 K −1 ) at a wide temperature range of 80–300 K. In particular, the remote thermography is established with a high spatial resolution of −20 lp mm −1 by processable thin films. These findings enhance the potential for molecular‐level illumination in Cu(I)‐based halides and contribute to the exploration of their optoelectronic properties.