A new subclass of copper(I) hybrid emitters showing TADF with near-unity quantum yields and a strong solvatochromic effect.

We introduce here a new subclass of copper(I) hybrid emitters simultaneously containing [CuI] anions and Cu cations, separated in space by a Janus head ligand. When UV-irradiated at 298 K, these unique "Two-In-One" hybrids exhibit a short-lived green TADF with near-unity quantum yield and a strong solvatochromic effect. Moreover, they manifest a strong radioluminescence upon X-ray irradiation. These findings open up new possibilities for the design of highly performing TADF materials.