Purely organic near-infrared afterglow systems based on a triplet excimer donor

A kind of NIR afterglow with a lifetime of 0.16 s at 808 nm was prepared using triplet excimer (PVB@PVA) as the donor. PYB 2 @PVA containing more excimers is beneficial to improve luminescence of Cy7 acceptor via a triplet-to-singlet energy transfer.