Tunable emission color of [(2-mb)tpp]2Cd1-xMnxCl4 (x=0-1) solid solutions synthesized via mechanochemical method for anti-counterfeit luminescent paper and WLEDs

Zero-dimensional (OD) hybrid metal halides (HMHs) have received widespread concern due to their unique structures and splendid luminescent properties. However, the syntheses of HMHs primarily rely on crystal growth methods in solution or ion-thermal conditions, which are time-consuming and require extensive use of organic solvents. On the other hand, the reported HMHs usually exhibiting only one emission color hinder their further applications. Herein, we report a series of OD HMHs solid solutions of [(2-mb)tpp](2)Cd1-xMnxCl4 [(2-mb) tpp = (2-methylbenzyl)triphenylphosphine and x = 0-1] synthesized through a facile mechanochemical method. The emission color of [(2-mb)tpp](2)Cd1-xMnxCl4 can be tuned from purplish-blue, bluish-green, to green light by adjusting the Cd/Mn molar ratio or excitation wavelength. Thus different luminescent panda and quick response (QR) code patterns can be designed with [(2-mb)tpp](2)Cd1-xMnxCl4 as luminescent dyes for potential applications in multicolor imaging and anti-counterfeiting encryption. Moreover, owing to the excellent thermal stability, the as-fabricated white light emitting diode (WLED) with [(2-mb)tpp](2)MnCl4 as the green phosphor possesses an applicable correlated color temperature (CCT = 5305 K), an ultrahigh color rendering index (CRI, Ra = 95.4), and the CIE chromaticity coordinates of (0.3386, 0.3864) corresponding to pure white light. This work provides guidance for the rapid, facile, economical, and large-scale synthesis of HMHs with multiple luminescent centers, and exhibits the development of these materials in potential applications such as anti-counterfeiting luminescent papers and WLEDs.

Automated summary

This research presents a series of OD HMH solid solutions synthesized using a simple mechanochemical method. These materials exhibit multiple emission colors and show potential applications in multicolor imaging, anti-counterfeiting encryption, and white light emitting diodes.