Efficiency Enhancement in Polymer Solar Cells by Introducing Titanium Dioxide Layer

We demonstrate that high eciency polymer solar cells can be fabricated using titanium oxide(TiOx) as an optical spacer. When a TiOx layer is deposited via a typical sol-gel process between the active layer and cathode, the devices exhibit almost 50 % enhancement in the external quantum eciency and in the power conversion eciency. The a TiOx layer acts as an ideal optical spacer by modifying the distribution of the optical electric eld energy inside the device, thereby inducing more photogenerated charge carriers in the polymer solar cell.clos