Collaborative Research: Exploration of Near-Field Thermophotovoltaic Energy Conversion for Efficient Thermal Energy Recycling

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

CBET-1236239/1236052 PIs: Park/Cho A thermophotovoltaic (TPV) system is a promising energy conversion device that generates the electric power from the infrared thermal radiation. However, its low power throughput and poor conversion efficiency restricts the usage in practical applications. One solution for resolving these issues is to utilize near-field thermal radiation, which can exceed the blackbody thermal radiation by several orders of magnitude. However, due to difficulties in maintaining the parallel nanoscale gap between the emitter and the receiver, experimental investigations of near-field thermal radiation have been limited to simple spherical or point-like emitter geometries. This proposal thus aims to experimentally investigate near-field thermal radiation between planar structures within a submicron vacuum gap and its contribution to the near-field TPV energy conversion. The innovative aspects of the proposed research are (1) to microfabricate a suspended thermal emitter (heater) to achieve a uniform temperature and minimize conduction heat loss; (2) to vacuum-package the microheater with a diaphragm to allow thermal radiation as the only heat transfer mechanism between the heater and the diaphragm; and (3) to precisely control the vacuum gap between the heater and the diaphragm by changing the diaphragm curvature with the external pressure. This project will provide the quantitative measurement of the near-field radiative heat transfer between two parallel plates at vacuum gap distances of a few hundred nanometers. In addition, the advantage of near-field TPV energy conversion device will be systematically examined, which also will provide the measurements of the power throughput and conversion efficiency of the near-field TPV device. The theoretical aspect of this research will improve our fundamental understanding of near-field interactions between thermally emitted electromagnetic waves and nanostructures via surface plasmon resonance, scattering, diffraction, and photon localization. The success of the proposed research will enhance scientific and technological understanding of the nanoscale TPV energy conversion while promoting teaching, training, and learning. The PIs will put forth considerable efforts to involve graduate and undergraduate students, especially those from underrepresented group, in cutting-edge nanotechnology research. They will gain hands-on experiences in micro/nanofabrication, thermal and electrical characterization of micro/nanodevices, and near-field radiative heat transfer measurements. The outcome of the proposed research will be incorporated into courses, such as Micro/Nanoscale Energy Transport at URI, and disseminated to the public through Thermal-Fluids Central (http://www.thermalfluidscentral.org) and technical journals.