Photobleaching induced time-dependent light emission from dye-doped polymer nanofibers

Abstract

Photobleaching has a great impact on the light emission of dye-doped polymer nanofibers. Here, we report photobleaching induced time-dependent light emission along polymer nanofibers doped with Coumarin 6 and Lumogen F Red 305 via waveguiding excitation at a wavelength of 473 nm. A nanofiber with a diameter of 450 nm was observed with emission color changing from green to red after 57 minutes excitation with an optical power of 4 μW at 473 nm wavelength. Spectrum analysis indicates that the major emission peaks were shifted from 492 to 590 nm. The photoluminescence was further found changing at different rates along the nanofiber. The experiment infers that the light emission is a function of both time and position along the nanofiber.