Strong donor-acceptor interaction of difluoroboron β-diketonates with polyvinylcarbazole: Deeply red-shifted emission of charge-transfer complexes and exciplexes

Abstract

Donor-acceptor systems exhibiting exciplex luminescence attract much attention due to the wide prospects for their application in the field of OLEDs, nonlinear optics and lasers. Difluoroboron β-diketonates (BF2bdks) are a well-known class of organic dyes, which are able to form effective exciplex fluorescence, but this process has not received due attention for practical application. Strong donor-acceptor interaction in polyvinylcarbazole (donor) and BF2bdks derivatives (acceptor) binary system induces deeply red-shifted emission of charge-transfer complexes and exciplexes with a large bathochromic shift up to ∼170 nm relative to conventional monomeric luminescence. The results of quantum chemistry simulation are in agreement with the experiment data. Luminescence color tuning of the film are capable by the dye concentration, the donor-acceptor properties of the dye substituents and even the excitation wavelength. White light broad spectrum of a dual luminescence of the investigated binary systems has CIE chromaticity coordinates (0.35; 0.33) close to the standard neutral white light CIE coordinates (0.33; 0.33). This study will facilitate photophysical research and industrial applications of donor-acceptor binary systems based on polymer materials.