(2014) proposed that oxybenzone undergoes an electron-driven internal conversion to its keto-tautomer as an ultrafast relaxation pathway upon photoexcitation
as the central mechanisms for its protective activity.
The principal mechanism of UVTiO2 photocatalytic reaction is delineated in Fig 1, which normally clarified in three steps: i) photoexcitation
of electron-hole pairs; ii) transformation of charge; iii) depletion of charges for redox reactions.
This process of electron-hole pair generation is known as photoexcitation
. Photoexcited electrons can be utilized in the reduction of oxygen, and similarly, holes can be utilized in oxidizing water molecules which are adsorbed on photocatalyst surface.
Curiously, recent ultrafast spectroscopic measurements on optimized polymer:fullerene-based OPV systems indicate that charge carriers begin to appear [less than or equal to] 100fs following photoexcitation
[2, 12, 15, 19-22].
Khare, "Coupling of piezoelectric, semiconducting and photoexcitation
properties in NaNb[O.sub.3] nanostructures for controlling electrical transport: realizing an efficient piezo-photoanode and piezo-photocatalyst," Nano Energy, vol.
Due to the push-pull interaction, efficient internal charge transfer (ICT) can take place from the donor (D) to the acceptor (A) upon photoexcitation
, thus leading to a new absorption band at longer wavelengths  and producing appropriate molecular energy levels for high [V.sub.oc], good charge transport, and high [J.sub.SC], thus improving PCE .
Jensen et al., "Photoexcitation
cascade and multiple hot carrier generation in graphene," in 2013 Conference on Lasers and Electro-Optics Europe and International Quantum Electronics Conference, CLEO/Europe-IQEC, Munich, Germany, May 2013.
It is also well known that some [beta]-carboline derivates on photoexcitation
induce chromosomal damages in mammal cells and may disarm viruses and bacteria .
The optical isotopic selectivity is strongly dependent on the particular photoexcitation
scheme and its resonance ionization transitions.
Energy transfer in the photoexcitation
of [Sm.sup.3+]-implanted Ti[O.sub.2] thin films.
The unit cell was kept at dark dry cabinet to prevent surging current due to photoexcitation