Metastability Effects in Cu2O Solar Cells

23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 583-587
Cu2O based junctions exhibit several metastable effects upon illumination or reverse bias application. We show that these effects are related to the persistent photoconductivity in Cu2O substrates. We have investigated these phenomena measuring conductivity vs temperature, persistent photoconductivity decay, Capacitance-Voltage and capacitance transients at different temperatures. We show that it is impossible to explain these data using an electronic mechanism only. A new model which includes the formation-dissociation of intrinsic defect complexes (VCu-VO) can give instead a better agreement with the experimental data.