Graphene field effect transistors for detection of ionizing radiation

A novel radiation detector based on a graphene field effect transistor (GFET) is experimentally demonstrated. The detection in GFET relies on the high sensitivity of the resistivity of graphene to the local change of electric field that can result from ionized charges produced in the underlying semiconductor substrate. We present the experimental results of our study on the graphene-based radiation detector response to X-rays. We observed increasing resistance change of graphene with increasing X-ray flux in an electrically biased GFET based on a Si substrate. We have measured the temporal characteristics of our detector, along with the sensitivity of the device at high (40 kV-80 μA) and low (15 kV-15 μA) X-ray fluxes. Furthermore, we demonstrate room-temperature operation of a graphene radiation sensor based on a SiC absorber.