English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

In common nonpolar liquids, such as saturated hydrocarbons, a dynamicequilibrium between trapped (localized) and quasifree (extended) states hasbeen postulated for the excess electron (the two-state model). Usingtime-resolved dc conductivity, the effect of 1064 nm laser photoexcitation oftrapped electrons on the charge transport has been observed in liquid n-hexaneand methylcyclohexane. The light promotes the electron from the trap into theconduction band of the liquid, instantaneously increasing the conductivity byorders of magnitude. From the analysis of the two-pulse, two-colorphotoconductivity data, the residence time of the electrons in traps has beenestimated as ca. 8.4 ps for n-hexane and ca. 13 ps for methylcyclohexane (at295 K). The rate of detrapping decreases at lower temperature with anactivation energy of ca. 200 meV (280-320 K); the lifetime-mobility product forquasifree electrons scales linearly with the temperature. We suggest that theproperties of trapped electrons in hydrocarbon liquids can be well accountedfor using the simple electron bubble (Wigner-Seiz spherical well) model. Theestimated localization time of the quasifree electron is 20-50 fs; both timeestimates are in good agreement with the "quasiballistic" model. Thislocalization time is significantly lower than the value of ca. 300 fs obtainedusing time-domain terahertz (THz) spectroscopy for the same system [E. Knoeselet al., J. Chem. Phys. 121, 394 (2004)]. We suggest that the THz signaloriginates from the oscillations of electron bubbles rather than thefree-electron plasma; vibrations of these bubbles may be responsible for thedeviations from the Drude behavior observed below 0.4 THz. Various implicationsof these results are discussed.Comment: 37 page, 5 figures; w Supplement of 13 pages and 5 figures; accepted  by J. Chem. Phy

Photostimulated electron detrapping and the two-state model for electron transport in nonpolar liquids