▎ 摘　　要

As a one-atomic-layer carbon material with the symmetrical conduction and valence bands, graphene shows a lot of interesting effects under high electric field. Here, we report an observation of self-amplification effect of current in graphene transistors in high-field transport. The current in graphene transistors could increase with time and finally reaches up to the breakdown threshold of graphene, even under the fixed bias and zero gate voltages. The current self-amplification is accompanied by the enhancement of the graphene p-doping, which demonstrates that this effect arises from the electrons escaping from graphene due to joule heating. (C) 2014 Elsevier Ltd. All rights reserved.