On the improvement of the anode/organic material interface in organic solar cells by the presence of an ultra-thin gold layer

The energy conversion efficiency of organic solar cells based on simple electron donor/electron acceptor heterojunction has been studied as a function of the interface anode/electron donor. The anode is fluorine doped tin oxide film. It is shown that the solar cell efficiency increases when a metal ultra thin layer is introduced between the anode and the electron donor. Experimental and theoretical studies show that the work function value of the metal is one of the main factors which allow improving the organic solar cells performances, via better hole collection efficiency. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim