Graphene Tunneling Transit-Time Terahertz Oscillator Based on Electrically Induced p-i-n Junction

We propose and analyze a graphene tunneling transit time device based on a heterostructure with a lateral p-i-n junction electrically induced in the graphene layer by the applied gate voltages of different polarity. The depleted i-section of the graphene layer (between the gates) serves as both the tunneling injector and the transit region. Using the developed device model, we demonstrate that the ballistic transit of electrons and holes generated due to interband tunneling in the i-section results in the negative ac conductance in the terahertz frequency range, so that the device can serve as a terahertz oscillator. (C) 2009 The Japan Society of Applied Physics DOI: 10.1143/APEX.2.034503