Cary 500 spectrometer

Solution UV-VIS linear absorption spectra were collected with a Cary 500 spectrometer. Film UV-VIS linear absorption spectra were acquired with a Varian Cary-6000i equipped with an integrating sphere. For films, the absorbance was calculated as A = –log₁₀(R + T). Transient absorption datasets were acquired using a Coherent Libra Ti:sapphire laser, with an output of 800 nm at 1 kHz. A TOPAS-C OPA was used to generate the ∼150 fs pump pulse (center wavelength 530–650 nm). A small amount of 800 nm light was used to pump a CaF₂ crystal to generate 330–850 nm probe light for UV-VIS TA or a 1 cm thick sapphire crystal to generate 750–1640 nm probe light for NIR TA. A second TOPAS-C OPA was used to generate ∼150 fs 5–6 μm probe pulses for MIR TA. The instrument response function was ∼150–250 fs depending on the probe wavelength. A Janis VPF 100 Cryostat was used for all TA measurements under vacuum. A solution cell was assembled with an o-ring and sapphire windows in a glovebox for measurements with solvent and electrolyte present. All datasets were analyzed using Surface Xplorer software. Charge injection yields were determined by comparing the maximum signal of a Z907/TiO₂ sample to the maximum signal of an acene/TiO₂ sample of interest under identical excitation conditions.

UV-vis absorptions were measured using a Varian Cary 500 spectrometer (Varian, USA). Steady-state PL was measured using an Edinburgh Instruments FLS920P fluorescence spectrometer, and for PL life time measurement [time-correlated single-photon counting (TCSPC)], a picosecond pulse diode laser (EPL-405; excitation wavelength, 405 nm; pulse width, 49 ps) was used.