Tryptophan‐Doped Poly(vinyl alcohol) Films with Ultralong‐Lifetime Room‐Temperature Phosphorescence and Color‐Tunable Afterglow Under Ambient Conditions

Abstract

AbstractThe development of a persistent luminescence system with long‐lived phosphorescence and color‐tunable afterglow at room temperature represents a challenge, largely due to the intensive non‐radiative deactivation pathway. In this study, an ultralong‐lived room temperature phosphorescence (RTP) system has been achieved using a hydrogen‐bonding strategy where poly(vinyl alcohol) (PVA) matrices were doped with tryptophan (Trp) derivatives. The PVA film doped with N‐α‐(9‐Fluorenylmethoxycarbonyl)‐L‐tryptophan (Fmoc‐L‐Trp) exhibited a long‐lived phosphorescence emission of up to 3859.70 ms, and a blue afterglow for a duration greater than 34 s, under ambient conditions. The introduction of two other fluorescent dyes (i. e., Rhodamine B and Basicred14) to the PVA film facilitates adjustment to the color of the afterglow from blue to orange, and pink, by a triplet‐to‐singlet Förster‐resonance energy transfer (TS‐FRET) process. These films have been successfully applied in silk‐screen printing and in multicolor afterglow light‐emitting diode (LED) arrays.