NIRT: Nanoscale Engineering of Inorganic-Organic Interfaces: Applications to Molecular Scale Electronics

Cornell University, Ithaca NY

Investigators

Abstract

This proposal was received in response to the Nanoscale Science and Engineering Initiative, Program Solicitation NSF 01-157, in the NIRT category. The proposal focuses on developing novel chemical approaches to forming well-behaved and robust interfaces between small organic molecules and both conducting and insulating inorganic ultrathin films for applications in molecular scale electronics. Much of the success of present day microelectronics is due to the ability to integrate a variety of (mostly) inorganic materials into structures useful for devices. For example, silicon dominates the field not because of its intrinsic electrical properties, but because of the quality of the interfaces it forms (e.g., the Si-Si02 interface). The work to be conducted here seeks to develop organic-inorganic interfaces possessing equivalent or superior properties, where small organic molecules form the active layers. The solution lies in the development of chemically based approaches to the formation of the critical interface between the inorganic layers (both metallic and dielectric) and the organic layers. Success in this venture will require the application of sophisticated synthetic organometallic chemistry, surface and interface science, self-assembly and nanofabrication, and "chemically accurate' computer simulation. The team that has been assembled at Cornell possesses expertise and significant experience in all of these areas. The organic layers will typically be formed by a process of self-assembly (in solution or in vacuo) on substrates that have been patterned to expose selected areas comprised of metal (e.g., Au), oxide (e.g., Si02), or nitride where the self-assembled monolayer will bind. Study of patterned substrates is vital for the investigation of a number of issues, from the fundamental to those related to device design and performance. Ultimately the team seeks as a final set of goals: (i) development of novel organometallic precursors for the formation of both conducting and insulting layers that will interface seamlessly with the organic layer; (ii) development of a fundamental understanding of the interface formation process, including the effects of process variables such as temperature on the molecular scale structure of the interface; (iii) demonstration of controllable device properties for molecular scale electronics, given enhanced knowledge of the interfacial chemistry and physics; and (iv) development of computer models that can both predict the atomic scale structure of the interface, and the resulting electronic properties. A final significant challenge put forward by the Cornell team will be the development of a workshop on research ethics. From the experience of working to develop this workshop the participants hope to build a better understanding and recognition of responsible research conduct, and to know the relevant philosophical underpinnings of ethics sufficiently well to be able to make ethical choices in both the development and practice of their research.