Improving the electroluminescence performance of blue light-emitting poly(fluorene-co-dibenzothiophene-S,S-dioxide) by tuning the intra-molecular charge transfer effects and temperature-induced orientation of the emissive layer structure

摘要: We designed and synthesized a series of charge-carrier-balanced blue light-emitting poly(fluorene-co-dibenzothiophene-S,S-dioxide) (PFSO10) derivatives (PFTAsSO10 PFSO10TAs) by incorporating an electron-rich triphenylamine (TA) unit into the polymer. To effectively weaken intramolecular charge transfer (ICT) effects in electron-deficient dibenzothiophene-S,S-dioxide (SO) TA units polymer main chain, copolymers PFSO10TAs end-capped were one-pot Suzuki polymerization. Atomic force microscopy grazing incidence X-ray diffraction measurements revealed rougher morphology associated with enhanced ordering chains across entire film processed thermal annealing at 115 °C for 10 min. The introduction PFSO10 significantly improved electroluminescence (EL) performance blue-emitting polymers. device also showed stable EL spectra varying current densities from 100 mA cm−2 to 800 temperatures 40 180 °C. single-layer based on PFSO10TA2 thermally annealed 80 outperforms those devices fabricated PFTAsSO10 copolymers. In particular, was dramatically min, resulting maximum luminous efficiency 7.30 cd A−1 Commission Internationale de L’Eclairage coordinates (0.16, 0.15) very slow roll-off. could be attributable relatively weak ICT effect, electron hole transport balance more ordered stacking thin film. These results demonstrate that tuning effect temperature-induced orientation promising strategy achieving high-efficiency blue-light-emitting devices.