Fig. 3: Transient absorption spectroscopy studies of the IR806-BTTQD 2 TTA-UC system.
From: Molecular near-infrared triplet-triplet annihilation upconversion with eigen oxygen immunity
a, b Femtosecond transient absorption spectra of IR806 (a) and IR806-BTTQD 2 (b) in deaerated chloroform using 800 nm pulsed laser excitation (2 μJ, FWHM = 50 fs), with corresponding transient kinetics of singlet (S1) decay and triplet (T1) rise shown below (down panel). c, d 2D nanosecond transient absorption color plots of IR806 (c) and IR806-BTTQD 2 (d) in deaerated chloroform using 700 nm pulsed laser excitation (2 μJ, FWHM = 50 fs), with corresponding transient kinetics at 580 nm in deaerated and aerated chloroform shown below (down panel). e Simplified Jablonski diagram showing the dominant photophysical routes and rates involved in IR806 (left) and IR806-BTTQD 2 (right) TTA system. a–d cIR806 = 1 × 10−5 M, cBTTQD = 1 × 10−4 M.
