Method of making an array of interconnected solar cells

Thin film organic solar cell array comprising a layer stack having a prescribed thickness (t) disposed on a flexible substrate, the layer stack comprising upper and lower polymer conductive layers having an organic photoactive layer and a semi conductive electron transport layer interposed there between;

• at least one contact hole in the layer stack completely extending through the upper conductive layer and the organic photoactive layer, the contact hole having a depth less than the prescribed thickness (t);
• at least one first heat affected zone operable as an electrically insulating barrier at a first centre-to-centre distance (s1) from the at least one contact hole and having a depth equal to the prescribed thickness (t) of the layer stack, and at least one second heat affected zone operable as an electrically insulating barrier at a second centre-to-centre distance (s2) from the at least one contact hole and having a depth of a combined thickness of the upper conductive layer and the photoactive layer, wherein
• the first and second heat affected zone each provide an increased electrical resistivity to the layer stack, and
• at least one electrical connecting member at least in part continuously covering the at least one contact hole, the at least one first heat affected zone and the upper conductive layer distal to the at least one contact hole.