An increase in the LCB density also significantly reduced the ratio of loss modulus over storage modulus, and yielded longer relaxation lifetime and higher level of extrudate swell.
Results on related parameters such as high frequency dielectric constant, plasma frequency, relaxation lifetime, electron density, film thickness and band gap are discussed.
Assuming that the fundamental polaron relaxation lifetime for P3HT does not change with increasing PCBM concentration, this trend can be explained by the independent or combined action of increased production of polarons and/or reduced availability of electrons for recombination.
Fitting of relaxation lifetime of the negative signal for the sample excited at 627 nm, using exponential decay function on TAS traces at 550 nm (we tried to avoid noises at 500 nm) provides a value of 0.36 ± 0.04 ps (Table 1).
The decay function is a triple-exponential decay with the formula 1where A0 is an offset, n is the number of exponentials to fit, A n is a preexponential factor, τ n is the relaxation lifetime of the sample, and x0 is the time offset.
In the WT and each of the mutants, we observe a single phase in the fluorescence relaxation kinetics, corresponding to the slowest IR-probed relaxation lifetime; we have already assigned the latter to folding of the second strand of the β-sheet.
