A process for making a photovoltaic device

A process for making a photovoltaic device, comprising: a substrate; a first electrode on the substrate; a second electrode on the substrate; a semi-conductive double layer comprising a first continuous sub-layer which is a second continuous lower layer in contact, wherein the semi-conductive Double layer located on the substrate between the first electrode and the second electrode, the first sublayer spatially closer to the first electrode is as the second sub-layer; and an electron transporting layer between the second underlayer and the second electrode; wherein a transition between the first sublayer and the second sub-layer of semi-conductive Double layer has a surface roughness of 1 nm to 6 nm, wherein the semi-conductive double layer is produced as follows: a) applying a first sub-layer of a polymorph of a metal phthalocyanine; b) carrying out a chemical and / or thermal treatment to the applied in step a) layer, which is converted into a different polymorph, the polymorph; and c) applying a second sub-layer of the same polymorph of the metal phthalocyanine from step a) on the first sublayer.