Illumination time

FIG. 62. Normalized solar cell efficiency as a function of illumination time for different power densities as obtained by continuous illumination of 1000-W/m" AM 1.5 light. The initial efficiencies of the four cells were 9%, 109f. 9c. and 69c for 28-. 42-. 57-. and 113-mW/cm power density, respectively. 

Smith et al. [602] have derived the dependence of FF on illumination time. They combined the empirical relationship between FF and d. [Eq. (70)] with the time dependence of the defect density (NdbU) [89]) and the relation be-... 

Figure 12.8. Transformation activity (streptomycin resistance) of a DNA-yeast extract mixture as a function of illumination time. (Reproduced with permission from Ref. 74.)...

Figure 2. Absorbance decay of benzoin ethyl ether at 328 nm as a function of illumination time. The experiments were performed on 3.0 ml solutions of 0.1 wt. % BEE in 1-propanol.

Figure 10. Flexural modulus as a function of illumination time for photocured composites with fiber loadings of 0, 25, and 50 wt.%.

Since the reactions were carried out in neat-liquid phase, the initial number of moles of reactant (ca. 0.8) is orders-of-magnitude greater than the radiant flux (7 10 7 Einstein.s l 1 Einstein = 1 mole of photons). This means that the conversion remains small (< 1%) for an illumination time of a few hours, given the quantum yield (see section 2.4). The advantage of these low conversions is that true kinetics can be determined because of the absence of inhibition by the products or of possible photochemical transformations of the products. 

KOH is a deliquescent basic electrolyte like NaOH, and its coating on Pt/Ti02 makes possible gas-phase water photolysis as described earlier for Sri i03 crystal.8) In experiments similar to that shown in Fig. 13.6, the yield is maximized at ca 0.12 ml of KOH solution.16) The maximum yield is, however, less than one half the maximum yield in NaOH solution.,6) In addition, the photocatalytic activity of Pt/Ti02 declines with illumination time in KOH solution by unknown mechanisms. 

Figure 1. Changes in the 18q16o/18o2 ratio and in the isobutane concentration in gas phase over Ti02 as a function of illumination time...

Figure 2. Changes in the isotopic composition of gas phase oxygen and declines of 0 isotope content of gaseous oxygen or nitric oxide as a function of illumination time for preoxidized Ti02 samples.

Figure 8. Rate of photocleavage of acetylene (C2H2) and methyl-acetylene (03 ) as a function of illumination time, a) Methane (CHi ) from acetylene and c) ethane (C2H6) from methylacetylene using meso-Zn-tetramethylpyridinium porphyrin as sensitizer, b) Methane (CHi ) from acetylene and d) ethane (C2H6) from methylacetylene with Ru(bpy)f as sensitizer.

Fig. 6.11. Size distribution of Ag nanoparticles photodeposited onto Ti02 electrode in different conditions 1 - light intensity 1 mW/cm2, illumination time 100 s 2 -10 mW/cm2, 10 s 3 -100 mW/cm2, 1 s 4 - pulsed UV irradiation, 40 W/cm2, 2 ms.

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