Graphene-based materials are suitable candidates as electrode materials for eliminating many drawbacks(e.g.,brittleness)associated with common organic light-emitting devices(OLEDs)comprising tin-doped indium oxide anodes.Unfortunately,relatively low luminous efficiencies are generally observed in most graphene-based OLEDs due to low work function and large sheet resistance of the graphene.Here,we report the experimental observation of negative differential resistance and hysteresis phenomena in graphene-based OLEDs and their effects on device performance.