Novel axially substituted phthalocyanine (Pc) absorber molecules are synthesized and applied as monolayer termination on indium-tin-oxide (ITO) substrates used as front electrode in ZnPc/C-60 organic solar cells. The presence of the chemisorbed molecules on the ITO surface is proven through near edge X-ray fine structure and X-ray photoelectron spectroscopy. The substrates work function increased from 4.3 to 5.0 eV close to the ZnPc highest occupied molecular orbital. Devices made on thus terminated ITO substrates show improved cell parameters. The new concept of absorber molecules with polar linkers as termination forms a band aligned pi-pi interface at the front contact raising the power conversion efficiency by 67% up to eta = 2%. (C) 2011 Elsevier B.V. All rights reserved.