Low-Energy Photoemission Study of C60/Rubrene/Au Interfaces in Practical Device Thickness

Low-energy photoelectron spectroscopy combined with photoelectron yield spectroscopy was developed to investigate the buried organic interfaces in the practical device thickness. Ultralow background signal and charging durability were achieved by utilizing monochromatic low-energy photons. C 60 /rubrene/Au interfaces were studied as a prototypical system of organic solar cells. The low density of gap states was detected in the rubrene film and a small feature due to the C 60 -induced morphological change was observed in the C 60 /rubrene interface.