Department of Chemistry
James Cahoon

James Cahoon

Assistant Professor
jfcahoon@unc.edu
919-962-3386
919-962-2388 (fax)
Caudill 019

 

Research Interests

Nanomaterials/Nanowire Synthesis, Nanostructured Solar Cells, Thermal Energy Harvesting, Interfacial Energy Transport, Photonics/Plasmonics

Professional Background

B.S. Chemistry & Philosophy, College of William and Mary (2003); Ph.D. Physical Chemistry, University of California-Berkeley (2008); IC Postdoctoral Fellow, Harvard University (2009-2011); Packard Fellowship for Science and Engineering (2014); ACS Physical Chemistry Division Post-doctoral Research Award (2010); National Science Foundation Graduate Research Fellowship (2004); Barry M. Goldwater Scholarship (2002).

Research Synopsis

The Cahoon group focuses on the synthesis of novel nanoscale materials with applications in solar and thermal energy, electronics, and photonics. A primary focus is the synthesis of complex semiconductor nanowires that can function as (1) nanostructured solar cell devices, (2) a platform for semiconductor/molecule interfaces, or (3) 1-dimensional components of photonic devices. The approach is multidisciplinary, interfacing chemistry, physics, materials science, and engineering. Students gain extensive experience in materials synthesis, nano/microfabrication techniques, electronics, optics, and spectroscopy.

Nanomaterial/Nanowire Synthesis
A state-of-the-art Chemical Vapor Deposition (CVD) system is used to synthesize 1-dimensional semiconductor nanowires by a Vapor-Liquid-Solid (VLS) growth mechanism. A focus is placed on development of new materials and synthetic methods that combine several components (e.g. Si, Ge, CdS, SiO2, Al2O3, etc) and provide detailed control of shape and morphology at the nanoscale. These novel materials are the basis for applications in solar energy, semiconductor-molecule interfaces, thermal energy transport, and photonics.

Nanostructured Solar Cells
Solar energy has the potential to fulfill worldwide energy requirements, however, low efficiencies and high costs will prevent widespread usage unless there is a breakthrough on these fronts. Nanostructured photovoltaic devices are a promising direction for development of high-efficiency, low-cost devices. Semiconductor nanowires provide a self-contained system which can separate charges (electrons and holes) on fast time scales and short (10-100 nm) length scales. These properties can be exploited to develop a new class of solar cell that achieves high efficiency with a low volume of material (i.e. low cost). This research effort encompasses the development of new synthetic methods, fabrication of solar cell devices, and measurement of both electronic performance and optical characteristics.