Probing Electronic Properties of Graphene on the Atomic Scale by Scanning Tunneling Microscopy and Spectroscopy

Atomic scale investigations of the electronic properties of graphene are playing a crucial role in understanding and tuning the exotic properties of this material for its potential device applications. Scanning tunneling microscopy (STM) and spectroscopy (STS) are unique techniques for atomic scale investigations and have been extensively used in graphene research. In this article, we review recent progresses in STM and STS studies of the electronic properties of suspended graphene as well as graphene supported by different substrates including graphite, metals, silicon carbide, silicon dioxide and boron nitride.

Graphene-based Bolometers

To achieve the state-of-the-art photon detectors, extensive research has been carried out on graphene-based bolometers. These utilize graphene’s promising properties including its small heat capacity, weak electron-phonon coupling, and small resistance. This article reviews the recent development of cryogenic graphene-based bolometers, which are of particular interest and importance for understanding as well as for taking advantage of the intrinsic properties of graphene. We summarize the major theoretical and experimental developments in the field, including the phonon cooling mechanism and its dependence on temperature, doping, and disorder, and the experimental approaches for realizing bolometric detectors.We also estimate the ultimate performance of an ideal graphene bolometer as a power detector and a single-photon detector if superconducting contacts are employed.

Techniques for Production of Large Area Graphene for Electronic and Sensor Device Applications

Here we review commonly used techniques for the production of large area and high quality graphene to meet the requirements of industrial applications, including epitaxial growth on SiC, chemical vapour deposition (CVD) on transition metals and growth from solid carbon source. The review makes a comparison of the growth mechanisms, quality (such as mobility and homogeneity) and properties of the resultant graphene, limitations and the prospect of each production method. A particular focus of the review is on direct (transfer free) growth on dielectric substrate as this is potentially one of the promising techniques for graphene production which can readily be integrated into existing semiconductor fabrication processes.