Zero-Dimensional Halides with ns 2 Electron (Sb 3+ ) Activation to Generate Broad Photoluminescence.

Organic-inorganic metal halides (OIMHs) have various crystal structures and offer excellent semiconducting properties. Here, we report three novel OIMHs, (PPA)InBr (PPA = [CH(CH)NH]), (PBA)SbBr, and (PBA)SbI (PBA = [CH(CH)NH]), showing typical zero-dimensional (0D) structure, octahedra dimers, and corner-sharing one-dimensional chains and crystallized in the monoclinic system with 2, 2/, and 2/ space groups, respectively. (PPA)InBr, (PBA)SbBr, and (PBA)SbI have experimental optical band gaps of ∼3.16, ∼2.24, and 1.48 eV, respectively. (PPA)InBr exhibits bright-orange light emission centered at 642 nm with a full-width at half-maximum of 179 nm (0.51 eV) and a Stokes shift of 277 nm (1.46 eV). After Sb doping, the peak position did not change, and the photoluminescence quantum yield increased significantly from 9.2 to 53.0%. The efficient emission of Sb:(PPA)InBr stems from the isolated ns luminescent center and strong electron-phonon coupling, making the spin-forbidden P-S observable. By combining commercial blue and green phosphors with orange-red-light-emitting (PPA)InSbBr, a white-light-emitting diode was constructed, with the color-rendering index reaching up to 92.3. Our work highlights three novel 0D OIMHs, with chemical doping of Sb shown to significantly enhance the luminescence properties, demonstrating their potential applications in solid-state lighting.