Yarmoff Research

Surface Transport in Organic Materials The possibility of novel effects in high mobility organic single crystal semiconductors includes two-dimensional superconductivity and molecular scale switching. We are making field effect devices from organic single crystals under conditions such that the electronically active crystal surfaces are well understood. This project is in collaboration with Profs. Mills and Haddon, and is funded by UCR's Center for Nanoscale Innovation for Defense (CNID). We initially demonstrated that an AlxGa1-xAs quantum well can be operated as an FET with an electron beam in place of the traditional metal gate. This allows for studies of atomically clean surfaces that would be damaged by the growth of a dielectric overlayer. We are now developing a contactless nanoscale method for introducing mobile surface charges on semiconducting organic and inorganic crystalline samples. We will investigate their fundamental surface conduction properties using vacuum-insulated gates and AC measurement techniques. These AC techniques and the high performance expected from good quality surface channels will enable new types of silicon- and organic-based semiconductor devices.