Fig. 5: RTP performance enhancement.
From: Building bridges through dynamic coupling for organic phosphorescence
a Chemical structures of 4 representative guest molecules used in the universality study (PZ, NA, BDZ and AN). b Delayed PL spectra of 4 representative host−guest systems used in the universality study, excited at 365 nm. c Chemical structures of modified host molecules. d Prompt and delayed PL spectra of PY−CzBP (top) and PY−BPCzA system (bottom) excited at 365 nm. Delay time: 10 ms. The emission of complex (LC) and phosphorescence of guest (PG) were noted. e Lifetime curves of complex emission in the singlet state (top) and triplet state (bottom) in PY−CzA, PY−CzBP, and PY−BPCzA. Emission wavelength recorded: 470 nm for PY−CzA and PY−CzBP; 500 nm for PY−BPCzA. f Calculated energy levels of PY−CzA and PY−CzBP systems. Possible ISC channels were represented by green arrows and ΔE values for ET process were noted. Insets: NTOs contributing to TH, TC, and TG transitions in these systems. Color code: green, hole; blue, particle. g The scheme representation showed that the intramolecular D-A structure of PY−CzBP/BPCzA systems accelerated the ISC process through providing more ISC channels and facilitated the decoupling process through lowering TH to serve as an additional bridge, to enhance the RTP performance. kISC, the experimental rate constant of ISC process; kET, the experimental rate constant of energy transfer process during decoupling. Blue spheres represented host molecules, and red for guest molecules. The green arrows represented the ISC process of complex and blue for ET process. h Lifetime curves recorded at PG in PY−CzBP/BPCzA, PY-d10−CzBP/BPCzA, excited at 365 nm. The fitted lifetimes were noted. i Photographs of PY-d10−CzBP crystals captured in air for 20 s after the 365 nm UV lamp was turned off.
