For LED applications, we selected PDI-coVPy-2.5% as a phosphor for commercial UV LED device by mixing it with polystyrene (MW of ~ 35,000 g mol -1 ) and drop casting. Due to the fact that pyrene shows blue-to-green emission under 365 nm, and the pyrene-to-PDI charge transfer was greatly weakened at a doping concentration of 1/1000 (w/w), bright white light emission was achieved for the produced polymer film. As a result, a white LED device was obtained with fluorescence color coordinates of 0.316, 0.338 on the CIE 1931 chromaticity diagram.