Photo generation

Semiconductor-electrolyte interface, photo generation and loss mechanism, 458 Semiconductor-oxide junctions, 472 Semiconductor-solution interface, and the space charge region, 484 Sensitivity, of electrodes, under photo irradiation, 491 Silicon, n-type... 

D-HYSCORE was used to characterize radicals of zeaxanthin and violaxanthin photo-generated on silica-alumina and to deduce the anisotropic a-proton hyperfine coupling tensors. The couplings (MHz) were assigned based on DFT calculations. From such a comparison, the presence of the neutral radicals formed by proton loss from the radical cations was confirmed. 

HYSCORE spectra of zeaxanthin radicals photo-generated on silica-alumina were taken at two different magnetic fields B0=3450G and B0=3422G, respectively. In order to combine the data from the two spectra, the field correction was applied (Dikanov and Bowman 1998). The correction consists of a set of equations that allow transformation of spectra to a common nuclear Zeeman frequency. The set of new frequencies was added to that of the former spectrum and plotted as the squares of the frequencies v2a and v2p. Examples of these plots can be found in Focsan et al. 2008. 

The organic substrate reacts directly with the photo generated surface holes and... 

The preparation of Titania nanocoils has been yet not investigated in literature. However, quite recent results258 show that the effective structure of Titania nanotube likely produced by controlled anodization process is that of a helical (compressed) nanocoil. Fig. 11 shows this concept. It was also demonstrated that the formation of these helical nanocoils improves the photo-generated current compared to samples after short anodization where only a Titania layer is formed. 

Anodic dissolution of n-Si can also proceed at a polarization under illumination. The maximum current is limited by illumination intensity when the saturation photo current density is lower than the critical current, Ji. The characteristics of i-V curves of n-Si under a high illumination intensity, when the reaction is no longer limited by the availability of photo generated carriers, is identical to that for p-Si. Similar also to p-Si, formation of PS on n-Si occurs only below the critical current, Jx 24... 

Me) ] photo-generated and do they persist in solution Photolysis of rigorously degassed benzene solutions of [MoH dppe ]... 

The kinetics of the reactions of photo-generated CH2CI, CHBrCl, CCI3, and CHsC Cla radicals with CI2 have been measured. In addition, the transition states for the four reactions were localized and optimized at the MP2/6-31G(d,p) level of theory. The kinetics were found to be controlled by the electronic nature of the substituents. ... 

Figures 4 and 5 show an n-type semiconductor with a surface depletion layer, the energy bands bending upwards as the surface is approached from the interior. Under illumination (Figure 5) the band bending is diminished because of the photo-generation...

The limiting factors that control photocatalysis efficiency are rapid recombination between photo-generated charge carriers, and the backward reaction leading to recombination of the formed molecular hydrogen and oxygen. To retard these processes efforts have typically focused on surface modification of the semiconductor particles using metals or metal oxides. 

Both photocurrent magnitude and photoconversion efficiency were observed to increase with the nanotube array film thickness. Fig. 9 evidences that a linear relationship was observed between film thickness (in the 2-6 micron range) and rate of H2 photo-generation. ... 

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