This project involves the formation of a new material with unique properties that could potentially be used to develop and improve on a range of functional devices. One of the most exciting new materials is called graphene, atomically thin sheets of carbon in the shape of "chicken wire" with properties never seen before. It is anticipated that radio-frequency devices will improve dramatically when graphene is incorporated. Calculations suggest that silicon and germanium may form analogs of graphene: silicene and germanene, respectively. However, stand-alone sheets of those materials have not been realized in laboratories. Most attempts to form them have involved high temperatures. Work by this research team has involved the use of electrodeposition, a room-temperature growth technique, and the results so far have been encouraging. The primary importance of this project, besides the formation of germanene, is the training of future scientists. This research group is composed of a mix of undergraduate and graduate students, half of whom are women. Results of this project are published in the peer reviewed literature and described in presentations at national and international scientific meetings.
This research project is on the growth and characterization of germanene, the Ge analog of graphene. Ab initio calculations have indicated that germanene should be stable and have properties similar to graphene. Formation of germanene has not yet been reported in the literature, however. The Si analog of graphene, silicene, has been reported, though only as single atomic layers of covalently bound Si on metal surfaces in vacuum. This project involves developing chemical methods to grow germanene nanofilms via the electrochemical analog of atomic layer deposition (E-ALD), and determining the mechanism for its growth and optimization. Characterization of the structure, morphology and composition of deposits is performed with surface analytical methods such as photoelectron spectroscopy, low energy electron diffraction, in-situ scanning tunneling microscopy, as well as with thin film techniques such as microprobe, X-ray diffraction, transmission electron microscopy, and Raman spectroscopy (including in-situ Raman measurements). The project also attempts to develop methods for removing germanene from the substrate so that its intrinsic properties can be better measured.
