Series Circuit of Organic Thin-Film Solar Cells for Conversion of Water into Hydrogen

A series circuit of bulk hetero-junction (BHJ) organic thin-film solar cells (OSCs) is investigated for electrolyzing water to gaseous hydrogen and oxygen. V-oc) of 3.4 V, which is enough to electrolyze water. J(sc)), fill factor (FF), and energy conversion efficiency () are independent of the number of unit cells. A maximum electric power of 8.86 mWcm(-2) is obtained at the voltage of 2.35 V. By combining a water electrolysis cell with the series circuit solar cells, the electrolyzing current and voltage obtained are 1.09 mA and 2.3 V under a simulated solar light irradiation (100 mWcm(-2), AM1.5G), and in one hour 0.65 mL hydrogen is generated.