Role of electrode buffer layers in organic solar cells

A systematic study on the energy level alignment, electron doping, and exciton quenching at interfaces between bathocuproine (BCP) buffer layers and various types of metal cathodes in organic solar cells (OSCs) was carried out by performing ultraviolet photoelectron spectroscopy (UPS), electronic conductivity, and photoluminescence (PL) measurements. Suppression of energy losses, such as low contact resistance and reduction of exciton quenching, were found at the metal cathodes with the BCP buffer layers. Impact of buffer/cathode interface properties on the performance of OSCs is discussed in detail.