Average oscillator strength

In terms of the average oscillator strength we can write the A coefficient as... 

Fig. 4.1 Oscillator strength distribution from the H Is state to the excited p states. Below the ionization limit the area of each block corresponds to the average oscillator strength...

Figure 5 The distribution function (77) of the peak heights within the interval A is plotted schematically versus x = CjCt- The minimal value of x is x m 1, while max 1. The point x = corresponds to the average oscillator strength.

To obtain the necessary parameters for (lIIB-33, 34) we look at the absorption spectrum of the molecule. The positions of the absorption maxima immediately give us the vs. The ji s are related to the integral of the absorption coefficient. We can define an average oscillator strength /j related to the average absorption coefficient by... 

Thus, in the saddle-poinl approximation, the absorption coefficient is the product of the averaged density of states (which is essentially the probability to find the necessary disorder fluctuation) and the oscillator strength of the optical transition between the two inlragap levels ... 

From Eq. (3.28), one finds that the oscillator strength is proportional to the square of the soliton-anlisolilon separation R. Using this, Eq. (3.33) reduces to the following form for the average absorption coefficient at low photon eneigy ... 

This result is further supported by the very short 130 + 10 ps lifetime combined with the remarkably high quantum yield of 0.43, both observed upon excitation at 335 nm, near the long-wavelength edge of the absorption band. These values combine to a radiative lifetime of 300 ps, which corresponds (33a) to an oscillator strength of 1.8. Similarly short emission lifetimes have been observed for other poly(di-n-alkylsilanes) di-n-pentyl, 200 ps, di-n-decyl, 150 ps. The average oscillator... 

At the temperature where the experimental lifetime was measured, the C and D states are about equally populated. Therefore the average of their oscillator strengths was used for the calculation of the lifetime. b From Ref. [39],... 

Livg average energy of configuration fED F hq oscillator strengths... 

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