Operation stability enhancement in organic photovoltaic device by a metal doped organic exciton blocking layer

While metal diffusion in organic layers have been considered as causes for performance degradation in organic light-emitting devices, we show that suitable metal doping can instead improve physical stability of organic films. By using a metal doped organic exciton blocking layer (EBL), enhanced stability is demonstrated in unpackaged CuPc/C60 organic photovoltaic devices (OPV). While devices with a pure organic EBL of bathocuproine and tris(8-hydroxyquinolinato)aluminum (Alq3) show over ∼20% decreases in efficiency for first 150 min of operation, the device with magnesium-doped Alq3 EBL shows less than ∼5% variation in efficiency during the same period.