This experimental project focuses on the properties of interfaces involving thin films of C-60, including alkali-metal-doped C-60 solids, and configurations which might be of interest in electronic devices. In the work, C-60 will be deposited sequentially or simultaneously with various metals, insulators or semiconductors. A variety of deposition techniques will be used including thermal sublimation, ion-beam sputtering and electron beam heating. In-situ characterization will primarily be accomplished by electrical transport measurements during and after deposition. These measurements involve not only in-plane transport but also tunneling and electric field effect measurements. For air-stable or passivated samples, additional characterization by x-rays, AFM, STM, magnetotransport, and optical and infrared absorption will be made. The high electron affinity and the relative ease of intercalation of C-60 will be aspects central to the research projects. One project will involve electron tunneling in trilayer structures to further understanding of superconductivity in the alkali-doped compounds and to determine the interface-related vibrational and electronic states and the expected relatively large Coulomb gap of molecules isolated in the tunnel barrier. This research project is interdisciplinary in nature and will involve graduate and undergraduate students who will be excellently trained for careers in industry, government and academia. %%% This experimental project is based on novel and potentially very useful electronic conducting films based on carbon-sixty molecules. Such molecules are like hollow spheres comprised of sixty chemically bonded carbon atoms, resembling tiny soccer balls. These molecules are relatively new and unexplored, especially in terms of their potential for forming insulating, electrically conducting, and even superconducting thin films. It has been possible to add alkali metals such as sodium or potassium to carbon-sixty to provide "electrical doping" which fosters electrical conduction and even superconductivity to temperatures up to about 30 Kelvin degrees. The work in this experimental project will, in part, involve "sandwich structures" which could perform functions which might be useful in electronic devices. This work will lead to a much better understanding of the electrical behavior of interfaces between conventional metals, insulators, and semiconductors, with films of the carbon- sixty molecules, and will possibly lead to applications for such interfaces. This research project is interdisciplinary in nature and will involve undergraduate and graduate students who will be excellently trained for positions in industry, government and academia. ***
