Indium-antimony-halide single crystals for high-efficiency white-light emission and anti-counterfeiting

Although single-source white emissive perovskite has emerged as a class of encouraging light-emitting material, the synthesis of lead-free halide perovskite materials with high luminous efficiency is still challenging. Here, we report a series of zero-dimensional indium-antimony (In/Sb) alloyed halide single crystals, BAPPIn(2–2x)Sb(2x)Cl(10) (BAPP = C(10)H(28)N(4), x = 0 to 1), with tunable emission. In BAPPIn(1.996)Sb(0.004)Cl(10), bright yellow emission with near 100% photoluminescence quantum yield (PLQY) is yielded when it was excited at 320 nm, which turns into bright white-light emission with a PLQY of 44.0% when excited at 365 nm. Combined spectroscopy and theoretical studies reveal that the BAPP(4+)-associated blue emission and inorganic polyhedron–afforded orange emission function as a perfect pair of complementary colors affording white light in BAPPIn(1.996)Sb(0.004)Cl(10). Moreover, the interesting afterglow behavior, together with excitation-dependent emission property, makes BAPPIn(2–2x)Sb(2x)Cl(10) as high-performance anti-counterfeiting/information storage materials.