Jiawei Lin, Yutong Lin, Lingling Mao
Halide perovskites have revolutionized optoelectronic materials research, yet their limited structural principles and narrow chemical space impose intrinsic limitations on property tuning. Hybrid metal halides (HMHs), as a broader class of materials, retain the organic–inorganic synergy of perovskites while breaking free from their structural constraints, featuring diverse coordination geometries, dimensionalities, and chemical compositions. This perspective synthesizes research findings based on our recent studies on HMHs, establishing a “component–structure–property” design paradigm. Key strategies include coordination geometry control, chirality induction, mixed-cation perturbation, dimensionality regulation, and heterometallic assembly, which enable precise modulation of photophysical properties such as high photoluminescence quantum yields, efficient circularly polarized luminescence, broadband emission, and nonlinear optical responses. Looking forward, we posit that the intentional exploitation of HMHs’ inherent structural versatility, guided by this design framework, will define the next frontier of functional hybrid semiconductors, pushing the boundaries of lighting, displays, and chiroptical technologies.