Gain of 56 in graphene silicon carbide schottky collector phototransistor (GSCBT) for radiation detection

Large low atomic number (Z) windows for novel solid state radiation detection schemes can be conceived by implementation of graphene semi-metal rectifying contacts on SiC epilayers and substrates. The low absorption of Graphene epilayers increases the incident flux/energy to the space charge region increasing detector charge collection. By implementation of a top graphene n-type schottky contact we report bipolar device operation in an epitaxial n-graphene/p-SiC/n-substrate vertical schottky collector bipolar transistor structure. The base current was supplied by e-beam irradiation of 15 keV on the p-SiC base layer. Transistor gains of up to 56 were obtained from the structure. Initial results suggest that gain improvements can be achieved by enhancement of the device interface, increased carrier lifetimes, and shortening the base region width.