Tailored Doping in Ionic Crystals for the Development of Color-Tunable Metal Halides through Solid-State Reactions

The rapid development of metal halides (MHs) in recent years has attracted significant attention. Doping, as a potent method for inducing new material properties, has also been extensively studied. This study focuses on the importance of doping as a universal strategy in the realm of optically active MHs in solid-state reactions. The method successfully incorporates 18 dopant ions into 12 MH hosts; a total of 34 doped MHs are achieved using the ball-milling method with the doping level approximately remaining at 5%. By strategically doping various ions, including Ag +, Sn 2+, Mn 2+, Ga 3+, Sb 3+, Cr 3+, Te 4+, Zr 4+, Nd 3+, Tm 3+, Yb 3+, Pr 3+, Er 3+, and W 4+ into the B-site of three distinct host materials (Rb 4 CdCl 6, Cs 2 ZnCl 4, Cs 2 NaInCl 6 ), we demonstrate the effectiveness and broad applicability of mechanochemical doping across different structures, achieving spectral tuning from 450 to 1550 nm. Moreover, doped MHs show a relatively enhanced trend in thermal stability compared to pristine MHs, which is attractive for the screening of emitters applied in solid-state lighting and displays. Consequently, this provides a straightforward and simple pathway for obtaining efficient light-emitting materials for optoelectronic applications.