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) 6 InBr 9 (PPA = [C 6 H 5 (CH 2 ) 3 NH 3 ] + ), (PBA) 2 SbBr 5 , and (PBA) 2 SbI 6 (PBA = [C 6 H 5 (CH 2 ) 4 NH 3 ] + ), showing typical zero-dimensional (0D) structure, octahedra dimers, and corner-sharing one-dimensional chains and crystallized in the monoclinic system with P 2 1 , P 2 1 / c , and C 2/ c space groups, respectively. (PPA) 6 InBr 9 , (PBA) 2 SbBr 5 , and (PBA) 2 SbI 6 have experimental optical band gaps of ∼3.16, ∼2.24, and 1.48 eV, respectively. (PPA) 6 InBr 9 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 3+ 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) 6 InBr 9 stems from the isolated ns 2 luminescent center and strong electron-phonon coupling, making the spin-forbidden 3 P 1 - 1 S 0 observable. By combining commercial blue and green phosphors with orange-red-light-emitting (PPA) 6 In 0.99 Sb 0.01 Br 9 , 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 3+ shown to significantly enhance the luminescence properties, demonstrating their potential applications in solid-state lighting.