Photoelectrical characterization of Schottky junctions between poly(4h-cyclopenta[2,1-b : 3,4-b']dithiophene) and aluminium: effect of hexadecyl groups in 4 position

The effect of hexadecyl groups in 4 position of poly(4H-cyclopenta[2,1-b:3, 4-b']dithiophene) was investigated. It was demonstrated that the steric inf luence of the alkyl-chains controls the structure and therefore the transpo rt properties of the polymers. The characterisation of the electrosynthetiz ed polymer films pointed out the more regular structure of the disubstitute d polymer and the higher compactness of the nonsubstituted one. These findi ngs were found to be in agreement with the photoelectric properties of the Schottky junctions between the three different polymers and aluminium. Bett er performance was achieved in the case of the non-substituted polymer. (C) 2000 Elsevier Science S.A. All rights reserved.