Trew, Kim Awarded for Thermal Energy Harvesting Research

June 02, 2009

Dr. Robert Trew, ECE Department, NC State University
Dr. Robert Trew, ECE Department, NC State University

Dr. Robert Trew and Dr. Ki Wook Kim have been awarded $320,000 by the Army Research Laboratory for research on Novel Nanoscale Technology for Thermal Energy Harvesting.

The award will run from May 19th, 2009 to November 19th, 2012.

Research Abstract - This research program proposes to explore the feasibility of engineering thermal radiation for application to thermal energy harvesting.  The approach is to utilize the high energy density stored in the evanescent field of surface excitations present on a thermal source composed of a polar semiconductor, by transforming it into spectrally and/or spatially selective radiation for ready extraction.

Dr. Ki Wook Kim, ECE Department, NC State University
Dr. Ki Wook Kim, ECE Department, NC State University

At nanoscale distances, near-field thermal excitations of polar semiconductors occupy narrow bands at THz frequencies. These excitations, in the form of surface waves, establish a quasi-coherent, evanescent field with high energy density.  Properly designed surface microstructures can convert the power available in evanescent modes to propagating modes with high efficiency.

The proposed effort is directed towards advancements in a theoretical model that can be used to both (1) investigate and develop an understanding of the fundamental physical mechanisms associated with the phenomenon, and (2) serve as an aid in designing experiments that can be used to verify the phenomenon, as well as serve as a guide to optimizing device structures.

Various test structures will be fabricated and tested in order to verify the theoretical predictions and demonstrate the feasibility of engineered thermal emission. A number of rectification schemes will also be investigated for harvesting the enhanced thermal radiation in the THz frequency and eventually converting it to the dc energy.