Gundlach, L. ; Ernstorfer, R. ; Felber, S. ; Eichberger, R. ; Willig, F.: Electron transfer from molecular chromophores to semiconductors probed with two-photon-photoemission. In: Welford Castleman, A. Jr. ; Kimble, M.L. [Eds.] : Femtochemistry VII: Fundamental Ultrafast Processes in Chemistry, Physics, and BiologyAmsterdam: Elsevier, 2006, p. 299-303
Abstract:
Heterogeneous electron transfer from the excited state of a molecular chromophore to empty electronic states of a solid is an important process in a variety of fields ranging from photo-chemistry [1] to molecular electronics [2]. In the last years numerous experimental and theoretical studies have addressed the dynamics of such processes. Light-induced heterogeneous electron transfer has been extensively investigated mainly with transient absorption in polycrystalline or nano-crystalline samples with anchored chromophores [3]. Transient two-photon photoemission (TR-2PPE) is capable of detecting the signals of sub-monolayer chromophore coverage on single crystal surfaces and gives information about the electron transfer dynamics, the position of the electronic levels at the surface, and the adsorption geometry of the molecules on the surface. Comparing the different 2PPE transients and the corresponding transient absorption measurements for identical systems revealed the origin of unexpected short time constants in the transient absorption measurements.