Zero-Dimensional Halides with ns2 Electron (Sb3+) Activation to Generate Broad Photoluminescence

Three new organic-inorganic metalhalides (OIMHs)and efficient luminescent OIMHs with broadband emission owing to thens(2) electron transitions of Sb3+. Organic-inorganic metal halides (OIMHs) have variouscrystalstructures and offer excellent semiconducting properties. Here, wereport three novel OIMHs, (PPA)(6)InBr9 (PPA =[C6H5(CH2)(3)NH3](+)), (PBA)(2)SbBr5, and (PBA)(2)SbI6 (PBA = [C6H5(CH2)(4)NH3](+)), showing typicalzero-dimensional (0D) structure, octahedra dimers, and corner-sharingone-dimensional chains and crystallized in the monoclinic system with P2(1), P2(1)/c, and C2/c space groups,respectively. (PPA)(6)InBr9, (PBA)(2)SbBr5, and (PBA)(2)SbI6 have experimentaloptical band gaps of & SIM;3.16, & SIM;2.24, and 1.48 eV, respectively.(PPA)(6)InBr9 exhibits bright-orange light emissioncentered at 642 nm with a full-width at half-maximum of 179 nm (0.51eV) and a Stokes shift of 277 nm (1.46 eV). After Sb3+ doping,the peak position did not change, and the photoluminescence quantumyield increased significantly from 9.2 to 53.0%. The efficient emissionof Sb:(PPA)(6)InBr9 stems from the isolated ns(2) luminescent center and strong electron-phonon coupling,making the spin-forbidden P-3(1)-S-1(0) observable. By combining commercial blue and greenphosphors with orange-red-light-emitting (PPA)(6)In0.99Sb0.01Br9, a white-light-emitting diode wasconstructed, with the color-rendering index reaching up to 92.3. Ourwork highlights three novel 0D OIMHs, with chemical doping of Sb3+ shown to significantly enhance the luminescence properties,demonstrating their potential applications in solid-state lighting.