Organic solar cells: from lab to Roll-to-Roll production

We report on a fully integrated roll-to-roll vacuum production process of small-molecule organic p-i-n tandem solar cells. The solar foils are prepared on a flexible PET substrate. Three different laser processes were developed to pattern the transparent bottom contact, the organic layers and the metal top contact. For the ramp up phase of the production tool, a simplified organic stack was developed to reach efficiencies above 5% with moderate complexity. The modules from Heliatek's roll-to-roll production show efficiencies of up to 6.8% on the active area of 1033cm(2) with a fill factor of 65.4%. Lab modules with the same layer stack on smaller samples prepared in a batch to batch process reach about the same values in all electrical parameters proving the excellent scalability of small-molecule p-i-n tandem solar cells prepared by vacuum deposition.