Unravelling the nature of unipolar resistance switching in organic devices by utilizing the photovoltaic effect.

The origin of resistive switching in organic devices is studied by photovoltaic methods and impedance spectroscopy. The results show that the most commonly proposed charging/discharging mechanisms can be excluded as working mechanism. There is solid evidence that resistive switching is due to the formation/rupture of filaments. Further, it is shown that this is a universal property of metal/organic/metal thin-film devices.