Morphology observations P3HT

Numerous other studies on the nanotube nanocomposites have been reported which demonstrate other properties like optical, morphological, fiber surface properties etc. Saini et al. (52) measured the UV absorption spectra of the poly(3-hexylthiophene) (P3HT) and its nanocomposites with varying amounts of nanotubes. The absorption band for pristine P3HT was observed at 505 nm which shifts toward the higher wavelength region on the addition of nanotubes... 

The formation and surface morphology of the coaxial P3HT/MWCNT hybrid NTs were investigated using HR-TEM, as shown in Fig. 27b [141]. The MWCNTs had an outer diameter of 10 30 nm and a wall thickness of 2—8 nm. The total diameter of the hybrid NTs was 60 nm. The thickness of the P3HT layer deposited on the MWCNTs was 20 ( 10) nm, and the formation of the coaxial-type MWCNTs coated with P3HT was clearly observed. 

Figure 59 Optical microscopy images for the blends of four different fullerene derivatives with P3HT. Obvious improvement of the active layer morphology with increase in the solubility of the fullerene derivatives can be observed. (Reproduced from Ref. 180. Wiley-VCH, 2009.)...

In another paper, it was demonstrated that CdSe nanocrystals can be dispersed efficiently in P3HT matrix by the use of binary solvent mixtures, in which one of the components is a ligand for the nanocrystals [255]. Optimization of the morphology of nanocrystal-polymer blends with solvent mixtures and thermal treatment to remove interfacial and excess of the solvents yielded high efficiency PV devices. A device fabricated from 90 wt% (7 x 60 nm) nanorods of CdSe in P3HT spin-cast from 4 vol% pyridine in chloroform and thermally treated at 120°C achieved a maximum EQE of 59% under 450 nm illumination at an intensity of approximately O.lmWcm", which is one of the highest EQEs observed in polymer blend PV devices [255]. 

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