Unveiling Doping Kinetics in Cu(I) Metal Halides for Customized Luminescent Performance

Intentional doping plays a pivotal role in customizing metal halides' electronic and optical features. This work manipulates the incorporation and distribution of Mn²⁺ in Cu(I) halide by controlling the elemental steps involved in the growth-doping kinetics as well as investigates the localized lattice and electronic structures in different doping configurations. Complementary experimental and theoretical results demonstrate that a uniform and relatively high Mn²⁺ doping level can be achieved by a step-tailored strategy that encompasses reducing the growth rate of the halide matrix, enhancing the surface adsorption of Mn²⁺, and facilitating the incorporation of the dopants. The optimized doping configuration mitigates severe lattice distortion and decreases the non-radiative transition rate, resulting in explicit dual-band emission and an enhanced photoluminescence quantum yield. This work underscores an effective synthesis strategy to harness the full potential of Mn²⁺-doped metal halides beyond Cu(I)-based ones and also showcases a new working paradigm of separately controlling the doping procedures for obtaining metal halides with customized optical/optoelectronic properties.