Short-Lifetime Blue-Emitting Dye for Electrospun Fibers with Potential for Light Fidelity Applications

Light fidelity (Li-Fi) is a wireless communication technology using visible light for data transmission via light-emitting diode (LED) modulation, offering enhanced security and immunity to radio frequency interference. Conventional white light Li-Fi systems rely on blue LEDs with rare-earth phosphors, whose microsecond-scale fluorescence lifetimes limit the modulation speed. We present alternative scalable organic dye-based platform 5-(2-ethylhexyl)-1,3-di(thiophen-2-yl)-4H-thieno[3,4-c]pyrrole-4,6(5H)dione (TAT), enabling subnanosecond lifetime and tunable blue to near-white emission. Electrospun TAT’s lifetimes, ∼0.64 ns, support high-speed modulation. Electrochemical modification yields E-TAT under an unconventional noninert atmosphere, maintaining ultrafast decay and shifting emission toward white light. Integration with near-UV LEDs allows chromaticity tuning to match daylight standards. Additionally, nanoprecipitation produces ∼86 nm fluorescent nanodots with narrow size distribution and stable emission, extending applicability to colloidal systems. This approach, from bulk dye to microfibers and nanodots, offers structural adaptability, spectral control, and an ultrafast response, enabling the development of Li-Fi-compatible lighting systems and integrating efficient illumination with high-speed data transmission.