The objective of this work is to investigate the controlled synthesis of a new material, graphene, that is structurally modified in order to artificially design its optical properties, and to characterize these for potential use in novel optoelectronic devices.
Intellectual Merit: The intellectual merit of the work lies in its value in advancing and contributing an original approach to controllably synthesize graphene. Its immediate impact is generation of new experimental results on purposely-engineered graphene. These results will lead to a new understanding of the optical properties of graphene for photonic device applications, thus contributing to advancing the field of photonics in particular, and materials in general.
Broader Impacts: In addition to creating new knowledge on a new material, this activity will broadly contribute to the training of (undergraduate and graduate) students in the conception, design, construction, and operation of a unique and original piece of equipment. It will extend the range of advanced instrumentation for research and education in photonics at Carnegie Mellon. The results of this work will be disseminated at key national and international conferences, including publications in leading journals, thus broadly impacting the field at large. If successful, the project has the potential to contribute to the understanding and development of a new material for nextgeneration concepts for advanced devices for information technology. Overall, the grapheotonics project represents the new frontier of nano-engineering at the atomic-layer level.It will create new material and knowledge for teaching and instruction in nanotechnology.
This Small Grant for Exploratory Research (SGER) supported the procurement and installation of several key components into a vacuum chamber designed for synthesis of single atomic layer and few atomic layers of carbon material on various extremely thin metal substrates. The metal substrates, nickel and copper, were about one thousandth of an inch or 25 microns thick. The objective of this work was to synthesize high quality, defect-free, carbon layers for future optical devices. Such exquisitely thin carbon layers are known as graphene, which is a derivative of graphite. Single-layer or few-layer graphene has fundamentally different properties from those of thick graphite material and is therefore of interest for scientific investigations and potential technological applications in future electronic and optoelectronic or photonic devices. Use of graphene for photonic devices could lead to a new field: grapheotonics. The graphene synthesized in this work was characterized by an optical technique known as Raman spectroscopy which yields results that can analyzed to assess the structural quality of the material. Properties of the electronic charge carriers in the graphene were extracted by applying an external voltage to a properly prepared sample of the material and measuring the resultant electric current. The measurements were correlated with others derived from a scanning atomic force microscope operating in what is known the Kelvin probe mode to assess the suitability of the graphene for light sensing applications. Preliminary light sensing device structures were fabricated and their basic electrical characteristics measured. Products of this Project: A fully functioning system for synthesizing graphene has been constructed and is available for graduate and undergraduate research and education in the department of electrical and computer engineering at Carnegie Mellon. One graduate student has been trained in the field of layered or two-dimensional materials. Furthermore, a first-year undergraduate student who was engaged as an assistant during the course of this research has decided, as result of his exposure to this field, to enroll in electrical and computer engineering. Finally, some of the technical results obtained during the course of this effort have been published in an archival journal and presented at an international technical conference (the American Physical Society Annual March Meeting of 2011).
