Spray coating fabrication of organic solar cells bypassing the limit of orthogonal solvents

The development of alternative deposition techniques is an important step towards the realization of low cost multilayered organic solar cells. While spin-coating needs orthogonal solvents to avoid an intermixing of stacked layers, thermal evaporation is expensive and not applicable to polymers. We show here how an innovative deposition technique called dry spray-coating may represent a promising way to manufacture bulk-hetero-junction (BHJ) and multilayered solar cells. Using standard materials such as poly(3-hexylthiophene-2,5-diyl) and [6,6]-phenyl-C61-butyric acid methyl ester, we achieved efficiency of 2.6% for the BHJ device, while a value of 1.5% was obtained for a bilayer structure using the same solvent for both materials. (C) 2013 AIP Publishing LLC.