Electron Transport at Nanostructured Semiconductor Interfaces

University Of Oregon Eugene, Eugene OR

Investigators

Abstract

The Analytical and Surface Chemistry program supports the project by Professor Mark Lonergan of the University of Oregon on fundamental studies with current-sensing atomic force microscopy of nanostructured semiconductor/polymer interfaces. Well-defined nanostructures will be fabricated using e-beam lithography to imbed an array of gold metal dots into an n-InP | polypyrrole interface. Electron transfer barrier heights and transmission coefficients will be measured in and around the nanostructures with probe microscopy. The goals of this work include: (1) to understand charge depletion and charge transport at laterally nanostructured interfaces, (2) to evaluate the efficacy of barrier inhomogeneity models in explaining classic anomalies, and (3) to develop current-sensing atomic force microscopy as a characterization tool for buried semiconductor interfaces. The project addresses a long-standing problem in the understanding of metal-semiconductor contacts, namely, the failure of models to adequately describe electron transfer, a key feature of an electronic device, semiconductor electrochemistry, and semiconductor/metal contacts. Model failure may be due to surface heterogeneity. Experiments are proposed to create well-defined nanostructures at a semiconductor interface, and then to measure the electron transfer rate and its temperature dependence across the nanostructure. The results will be used to assess and correct models of the semiconductor interface, accounting for nanoscopic features at the interface.