On the function of a bathocuproine buffer layer in organic photovoltaic cells

摘要

The role of bathocuproine (BCP) buffer layer inserted between active layer and Al contact in photovoltaic cells based on phthalocyanine (Pc) and C_(60) was investigated. Photoluminescence (PL) experiments show exciton quenching at the C_(60)-Al interface to be strongly reduced by inserting BCP. Current-voltage characteristics of photovoltaic cells with planar geometry front electrode/ Pc/C_(60)/BCP/Al show that BCP dramatically improves electron transport out of the C_(60) film into the Al electrode. The tenfold increase in power conversion efficiency (η) with BCP can mostly be attributed to the latter effect. BCP does not improve η in photovoltaic cells with blend film geometry front electrode/Pc:C_(60)/Al.