Near-infrared long-lifetime emission via triplet-to-singlet Förster resonance energy transfer

Here, an innovative approach to achieve near-infrared (NIR) long-lived circularly polarized luminescence (CPL) in amorphous organic polymer materials was achieved. By co-doping bi-naphthalene derivative R/S-BPN as energy donors with porphyrin derivative TPPOH as energy acceptor into PVA polymer matrix, the NIR long-lifetime fluorescence was successfully realized through the principles of triplet-to-singlet Förster resonance energy transfer (TS-FRET). Photophysical characterizations revealed distinct room temperature phosphorescence (RTP) emission peaks and phosphorescence lifetimes for different donor-acceptor ratios. The TS-FRET process facilitated extended lifetime and red-shifted emission of the acceptor TPPOH. Moreover, employing the chiral donor R/S-BPN as chiral seeds to establish chiral environments facilitated the achievement of near-infrared CPL. These findings offer a novel and practical strategy for achieving long-wavelength and long-lifetime CPL fluorescence without complex molecular engineering, presenting potential applications in various technological fields.