External quantum efficiency enhancement in organic photovoltaic devices employing dual organic anode interfacial layers

We demonstrate the use of a dual anode interfacial layer of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) and tetracene for efficient small molecule organic solar cells. These layers provided a multifaceted improvement on device performance by enhancing absorption in the donor layer, serving as an exciton blocking layer at the anode interface, providing a low resistance anode contact, and serving as a templating layer for increased crystallinity in the donor layer. Palladium phthalocyanine/C-60 planar heterojunction devices fabricated on top of the dual layers of PEDOT: PSS and tetracene demonstrates 85% enhancement in the donor contribution to external quantum efficiency and yielded a maximum power conversion efficiency of 3.66%. (C) 2013 AIP Publishing LLC.