ABSTRACT
The extraction of energy from solar light through optical processes in conjugated organic molecules is the basis of energy supply on Earth through photosynthesis. The conversion of optical energy to electrical energy in photovoltaic conversion technology is a much less advanced technology, but can deliver high conversion efficiencies with inorganic semiconductor crystals, which are expensive. The high photovoltages recorded in the polyfluorene–fullerene blend plastic solar cells and high quantum efficiency helps to generate solar cell efficiencies in the range of 2% to 3%. Size exclusion chromatography was used to determine the molecular weights. The analyses were performed on a Waters 150 Cyclic voltammetry equipped with a refractive index detector using 1,2,4-trichlorobenzene as solvent at 135°C. Calibration was performed with narrow molecular weight polystyrene standards. The purpose of the design of copolymers of fluorene and thiophene–lbenzothiazole–thiophene structures has been to generate optical absorption at lower energies by reducing the bandgap of the homopolymer polyfluorene.
