Photovoltaic properties of Schottky and p-n type solar cells based on polythiophene

The electrical and photovoltaic properties of organic Schottky and p-n type cells have been studied. Schottky devices are based on a spin-coated film of poly(3-butylthiophene) blend with the dye 1,3-bis-(dicyanomethylidene)-2-(4-dibutylaminobenzylidene)indane which is sandwiched between indium tin oxide (ITO) and gold electrodes. A depletion zone of 9.5 nm thick has been determined on a 220-nm-thick film. The conversion efficiency is equal to 0.01% under 100 mW cm(-2) white light illumination. Effects of dye loading, film thickness, and light intensity are described. A model based on simple assumptions is used to fit the photoaction spectra. By evaporation under vacuum of a layer of N,N-'-dimethyl-3,4,9,10-perylenetetracarboxylic diimide between the ITO and the polymer film, we have fabricated hybrid polymer-molecular p-n type photovoltaic cells. The role of this molecule in the photogeneration has been studied. A constant power conversion efficiency of 0.15% has been measured under white light illumination between 0.2 and 200 mW cm(-2). (C) 2001 American Institute of Physics.