Electrical switching characteristics of organic thin films made from branch chain substituted oligomer as measured by GaIn probe

In this paper, we report switching behaviors of organic thin films made from branch chain substituted oligomer with device structure of gallium indium eutectic cathode/organic layer(s)/anode (indium tin oxide, highly oriented pyrolytic graphite, copper or doped n-type silicon). The organic active layers were spin-coated from molecular solutions. The device current-voltage characteristics were investigated under ambient conditions, which revealed obvious switching performance of the as-fabricated devices with threshold voltage between 2.5 and 3.2 V and on/off ratio at order of magnitude of 101. To understand the switching mechanism, control experiments were carried out by systematically engineering the device active layer structure. The results suggested that the switching may be due to the charge trapping effects taking place in the organic layer.