Perpustakaan Digital ITB

Despite tremendous advances in improving the efficiency oforganic solar cells above 14%, the environmental stability of such devices remainsan essential and widely inadequately addressed challenge. Understanding theunderlying principles of device degradation is a critical step toward furtherdevelopment and commercialization of organic photovoltaics. Herein, we reporton the effect of oxygen exposure on the operation and degradation of highlyefficient PffBT4T-2OD:PC71BM photovoltaic devices. Ultrafast pump?probetransient absorption (TA) measurements and ultrasensitive photothermaldeflection spectroscopy (PDS) in combination withfield-effect transistorssuggest that oxygen-induced doping of the active layer is responsible for thesevere degradation of the photovoltaic performance. Wefind that light exposurefurther accelerates this effect without causing photo-oxidation of the materials.