Scanning the optical properties of 4-(1,1-difluoro-1H-1λ4,10λ4-benzo[4,5]thiazolo[3,2-c][1,3,2]oxazaborinin-3-yl)-N,N-diphenylaniline in mono-disperse and aggregation systems

Abstract

Organic molecules with hybridized local and charge transfer (HLCT) characters have attracted attention because of their potential in the field of two-photon fluorescence imaging and light-emitting diodes (LEDs). Herein, the 4-(1,1-difluoro-1H-1λ⁴,10λ⁴-benzo[4,5]thiazolo[3,2-c][1,3,2]oxazaborinin-3-yl)-N,N-diphenylaniline (TOND) molecule is studied through various spectroscopy tests to explore the solvent-dependent photo-physical properties in the mono-disperse system and temperature-dependent photoluminescence behavior in the aggregation state system. The monodisperse TOND shows apparent two-photon fluorescence properties and its absorption section enhances with solvent polarity owing to the intramolecular charge transfer (ICT) process. The solvent-dependent relaxation process of excited TOND, which is affected by the ICT process, is analyzed by pump–probe and pump–dump–probe tests. The aggregated TOND can be fabricated into an LED, whose emission peak is centered at 566 nm with the Commission Internationale de l’Eclairage chromaticity (CIE) coordinates of (0.47, 0.51). Their radiative lifetime and photoluminescence quantum yield together decrease with increasing temperature, due to the activation of the non-radiative process at high temperatures. Our results provide a comprehensive insight into the optoelectronic properties of these organic molecules.