Fig. 3: Photophysical mechanism investigation.
From: Building bridges through dynamic coupling for organic phosphorescence
a Three-dimensional (3D) contour map of fs-TA spectra for PY−CzA crystals measured at 267 nm excitation wavelength. Absorption of the singlet states of CzA and complex (SH and SC). b TA spectra of PY−CzA crystals and pure CzA crystals at a pump-probe delay time of 0.6 ps. c Absorption kinetics of SH in PY−CzA crystals and pure CzA crystals recorded at 650 nm. Fitted lifetime values and energy transfer efficiency were indicated. d Lifetime curves of emission from different species in PY−CzA crystals within a 50 ns range. Emission wavelength recorded for FH/G, 400 nm; LC, 470 nm; PG, 595 nm. The lifetime curve of PG generation was obtained through subtracting the LC component from the lifetime curve recorded at 595 nm. The time points at which the intensity of FH/G and LC reached their maximum were noted. e Temperature-dependent delayed PL spectra of PY−CzA at a delay time of 10 ms excited at 365 nm. f The proposed photophysical process of coupling-induced phosphorescence in PY−CzA system. ET, energy transfer; ISC, intersystem crossing. Blue spheres represented host molecules, and red for guest molecules. The gray arrows represented ET process, and green dotted arrows represented ISC process of complex.
