Imaging the Electric-Field Distribution in Organic Devices by Confocal Electroreflectance Microscopy

Space resolved Stark spectroscopy is introduced as a non invasive optical technique for imaging electric field distribution in organic semiconductors. Stark spectroscopy relies on the electric field induced change in the absorption/reflection. It is shown that local monitoring of Stark shift with confocal spatial resolution provides quantitative information on the strength of the local field as well as charge distribution within the transport channel. An optical technique to monitor electric field distribution in organic based devices is reported. By monitoring the Stark shift of molecular transitions with confocal microscopy information on the field strength within the device channel is obtained with sub‐micron spatial resolution. Large fluctuations across the interdigitated array associated to space charge accumulation are observed.