Organic solar cells all made by blade and slot-die coating techniques

In this work, polymeric solar cells with the configuration anode/Hole Transport Layer (HTL)/Active Layer/ Cathode, with an active area of 3 cm(2) were fabricated layer by layer, including the cathode, by doctor blade and slot-die techniques at normal room atmosphere and temperatures about 90 C-circle for cathode deposition. Further, small modules were built on a single substrate with 3 cells connected in series (active area of 9 cm(2)). The best electrical parameters for single cells were open circuit voltage (V-circle c = 571 mV, short circuit current density (J(sc)) = 7.69 mA/cm(2), fill factor (FF) = 0.55, and power conversion efficiency (PCE) = 2.4%, meanwhile for modules V-oc = 1.54 V, J(sc)= 2.09 mA/cm(2), FF = 0.55, and PCE = 2.1%. The main parameters of the deposition technique such as substrate temperature, blade speed and bar-substrate gap were evaluated to ensure the best photovoltaic (PV) device performance. For the active layer, a co-solvent system based on chloroform and 1,8 diioodoctane was used to dissolve the blend poly(3-hex ilthiophene-2,5dyil): [6,6]-Phenyl-C71-butyric acid methyl ester (P3HT:PC71BM). The utilized cathode, named Field's metal, was an eutectic alloy of Bi:In:Sn (32.5:51:16.5%) with a melting point about 65 C-circle; thus, this metal is easily melted and deposited by blading process on the active area. The obtained PV parameters demonstrate high viability of the bar coating process both for the fabrication of solar cells and small solar modules. (C) 2017 Elsevier Ltd. All rights reserved.