White light emission from an upconverted emission based on triplet-triplet annihilation with rose bengal as the sensitizer

In this work, we report an energy upconversion system based on triplet-triplet annihilation comprised of rose bengal dye as the sensitizer and a highly fluorescent 9-(triphenyl)ethynyl-10-phenylanthracene (TPE-PAn) as the triplet annihilator. The energy upconversion can be observed with a low-power laser excitation at 532 nm or noncoherent Xe arc lamp excitaion at 540 nm. A delayed fluorescence from (TPE-PAn) at 418 nm was observed with an energy upconversion up to 0.64 eV and quantum yield of 0.8 %. A white-light emission was achieved as a result of combination of delayed fluorescence from TPE-PAn and residual fluorescence from rose bengal dye.