Study of organic solar cells with stacked bulk heterojunction structure

Organic solar cells with stacked bulk heterojutaction（BHJ） are investigated based on conjugated polymer. By using the solution spin-coating method, Poly[2-methoxy, 5-（2＇ -ethyl-hexyloxy） -1,4-phenylene vinylene] （MEH-PPV） and ZnO nanoparticles （50 nm） are mixed as the optical sense layer. Ag is used as inter-layer to connect the upper BHJ cell and the lower cell. The structures are ITO/PEDOT：PSS/MEH-PPV lAg / MEH-PPV：ZnO/Al. The open circuit voltage （Voc） of a stacked cell is about 3.7 times of that of an individual organic solar cell （ITO/PEDOT：PSS/MEH-PPV/Al）. The short circuit current （Jsc） of a stacked cell is increased by about 1.6 times of that of individual one.