Transient Absorption Spectroscopy

Plasmon-Induced Hot Electron Transfer from the Au Tip to CdS Rod in CdS-Au Nanoheterostructures

“…In the small signal limit, where multiexciton states are negligible, the absorbance change of 1σ e electrons is proportional to the number of absorbed photons and the proportional factor is related to the absorption cross section and photon-to-1σ e electron conversion efficiency. 72 Because every absorbed 400 nm photon by free CdS NRs generates a 1σ e electron, the QY is given by the ratio of the TA signal sizes under 590 nm ΔA (590 nm) and 400 nm (ΔA (400 nm) ) excitation after correcting for the numbers of absorbed photons at these wavelengths according to eq 1:…”

“…Next, we seek to quantify the quantum yield (QY) of plasmon induced hot electron transfer in CdS-Au NRs using the signal size of the intraband transition of 1σ e electrons. In the small signal limit, where multiexciton states are negligible, the absorbance change of 1σ e electrons is proportional to the number of absorbed photons and the proportional factor is related to the absorption cross section and photon-to-1σ e electron conversion efficiency . Because every absorbed 400 nm photon by free CdS NRs generates a 1σ e electron, the QY is given by the ratio of the TA signal sizes under 590 nm Δ A (590 nm) and 400 nm (Δ A (400 nm) ) excitation after correcting for the numbers of absorbed photons at these wavelengths according to eq : QY = normalΔ italicA false( 590 nm false) ( 1 − 10 − OD ( 590 nm ) ) italicj false( 590 nm false) normalΔ italicA false( 400 nm false) ( 1 − 10 − OD ( 400 nm ) ) italicj false( 400 nm false) Here OD (590 nm) and OD (400 nm) are optical densities of CdS-Au at 590 nm and free CdS NR at 400 nm, respectively; j (400 nm) and j (400 nm) are the photon fluxes of 590 and 400 nm pump beams, respectively.…”

Challenges in Simulating Light-Induced Processes in DNA

“…One prominent method applied in experiments on DNA’s light-induced dynamics is transient absorption spectroscopy, where the initially photo-excited molecule absorbs further light, and the absorption spectrum of this second excitation is recorded [ 3 , 74 , 146 , 147 , 148 , 149 , 150 ]. In order to simulate transient absorption spectra, one needs to include additional excited states beyond the ones involved in the dynamics itself and incorporate all of the corresponding transition dipole moments in the dynamics calculations.…”

Elucidating Facet-Dependent Photocatalytic Activities of Metastable CdS and Au@CdS CoreShell Nanocrystals

“…The absorbance change of 1σ electrons is proportional to the number of absorbed photons. The proportional factor is related to the absorption cross section and the conversion efficiency of photon-to-1σ electron [8][9] . To improve the signal-to-noise ratio of the measurement, the measurement was carried out under different excitation pulse energies.…”