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We are developing detector architectures and devices based on the novel carbon nanomaterial graphene, which has been shown to exhibit unusual electrical properties of potential use for next-generation radiation detectors. Of particular interest is the use of this technology to develop novel neutron detectors. To this end, we are studying architectures based on a neutron-absorbing converter material in conjunction with a graphene field-effect transistor (GFET). As an intermediate step towards the demonstration of GFET neutron detectors we utilize an alphasource to systematically study the effect of charge deposition on the device response. As an added benefit, this experiment helps us elucidate the important systematics of response to other types of radiation, including the dependence of the magnitude of graphene resistance modulation on the deposited energy and the dependence of device speed on the morphology of energy deposition. [ABSTRACT FROM PUBLISHER]

Electron beam exposure is a commonly used tool for fabrication and imaging of graphene-based devices. Using Raman spectroscopy and electronic transport measurements, we have studied the effect of prolonged exposure of electron beams on exfoliated graphene on SiO2/Si substrates and the performance of electronic devices based on exfoliated graphene. Raman spectra indicate emergence of characteristic defects. Electronic transport measurements show an overall decrease in graphene's conductivity and a shift of the Dirac point. Our results are valuable for understanding the possible defects generated in graphene by electron beam exposure and in high-radiation environment in general. [ABSTRACT FROM AUTHOR]