Improvement of the photovoltaic properties of polythiophene-based cells

The photovoltaic properties of organic cells based on a polythiophene film have been studied. An external power efficiency of 10(-4)% has been obtaine d in the pristine polymer diode. In order to improve this result, three com plementary routes have been investigated. Optical sensitization of the poly thiophene with a dye of the indane group leads to a 75 increase in power ef ficiency. A hybrid molecular/polymeric p-n type junction instead of the ori ginal Schottky type provides a 0.15% efficiency. Molecular rectification in oriented polymers incorporating diodelike chromophores increases the PV ef ficiency by a factor of 40. (C) 2000 Elsevier Science B.V. All rights reser ved.