Electron hole pair creation

Direct verification of DR-mechanism of DIET was provided [21] by combining the state-selective photoexcitation of the sample and the controlled thermally induced release of electrons from electron traps (Fig.9a). In RGS, after electron-hole pair creation at selective excitation by photons with energies E>Eg, the hole may survive and be self-trapped if the electron is captured by any kind of traps [32], In solid Ar at T>2 K the main part of electron traps is not active [12], the electron-hole recombination occurs before self-trapping the holes, and, therefore, the concentration of W-band emitting centers decreases (Fig.9a). On the contrary, the heating... 

Atomic cryocrystals which are widely used as inert matrices in the matrix isolated spectroscopy become non-inert after excitation of an electronic subsystem. Local elastic and inelastic lattice deformation around trapped electronic excitations, population of antibonding electronic states during relaxation of the molecular-like centers, and excitation of the Rydberg states of guest species are the moving force of Frenkel-pairs formation in the bulk and desorption of atoms and molecules from the surface of the condensed rare gases. Even a tiny probability of exciton or electron-hole pair creation in the multiphoton processes under, e.g., laser irradiation has to be taken into account as it may considerably alter the energy relaxation pathways. 

Recent experiments determining the so-called chemicurrent [111] have provided some information on the importance of electron-hole pair excitation in adsorption processes. Using thin films deposited on n-type Si(l 1 1) as a Schottky diode device, the nonadiabatically generated electron-hole pairs upon both atomic and molecular chemisorption create the chemicurrent which can be measured [111, 112]. It has been estimated that for example in the NO adsorption on Ag one quarter of the adsorption energy is dissipated to electron-hole pairs. Adsorption-induced electron-hole pair creation has also been found for other metal substrates, such as Au, Pt, Pd, Cu, Ni and Fe, and even for semiconductors such as GaAs and Ge [112, 113]. 

The semiconducting polymer is locally oxidized and (nearby) reduced by photoabsorption and charge separation (electron-hole pair creation and separation into free carriers) ... 

Oclkrug et al. could not find any evidence of singlet oxygen in 5T aggregates, in contrast to solution [ 152]. Therefore a radiationless deactivation via internal conversion or sudden polarization (see Section 4.2) is concluded. The latter intermolecular electron-hole pair creation as decay channel is also proposed by the group... 

Ausman, Jr., G. and McLean, F. B., Electron-hole pair creation energy in SiO Appl. Phys. Lett. 26, 173 (1975). 

The dipoles of adsorbed molecules can couple through metal substrate electrons, partly contributing to the observed frequency shifts with the surface coverage [92, 128]. Finally, plasma oscillations of the metal electrons in the electric field of the IR beam (Section 1.3) can couple by an electron-hole pair creation mechanism with the adlayer modes whose dipole moment vector is parallel to the surface [129-132], Being forbidden (Section 1.8.2), these modes manifest themselves in metallic IRRAS as the so-called antiabsorption peaks (increase of reflectance). Examples are frustrated rotations of CO on Cu(lOO) and frustrated translations of H on W(IOO) and Mo(lOO) [129, 130]. This effect, however, should not be considered as the exception from the SSR for metals. 

Nienhaus H, Bergh HS, Getgen B, Majumdar A, Weinberg WH, McFarland EW (1999) Electron-hole pair creation at Ag and Cu surfaces by adsorption of atomic hydrogen and deuterium. Phys Rev Lett 82 446- 49... 

What is even more amazing is that the hydrophobic surface can switch reversibly between superhydrophobicity and superhydrophihcity when the solid surface is subject to UV radiation [63], which results in electron-hole pair creation [64]. After being stored in the dark over an extended period, the hydrophilicity is... 

WIT Witte, G., Weiss, K., Jakob, P., Braun, J., Rostov, K. L., Wdll, C. Damping of molecular motion on a solid substrate evidence for electron-hole pair creation Phys. Rev. Lett. 80 (1998) 121. 

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