Perovskite solar cells with versatile electropolymerized fullerene as electron extraction layer

An electropolymerized layer of a C60 fullerene derivative was successfully used as selective contact and electron transport layer in perovskite solar cells. The electropolymeric film was formed over FTO electrodes by an electrochemical methodology in just one step. The light emission of perovskite films formed over the electropolymer was quenched, confirming an efficient electron transfer from the perovskite to the electropolymerized C60 layer. Solar cells constructed with C60 polymer layer showed a much better performance compared with the same cell without the fullerene containing electropolymer layer. The best non-optimized device presented an efficiency of 11.0%, with an open circuit voltage of 969 mV, a short circuit current of 17 mA/cm2, and a fill factor of 65%. These results demonstrated that the use of an electrochemical methodology in the formation of an organic electron transport layers as replacement of metal oxides in perovskite solar cells opens a new approach in the fabrication of efficient energy conversion systems.