Efficient conversion of thermal radiation into electrical power has the potential to drastically reduce wasted energy and associated environmental impacts, such as greenhouse gas emission. Near-field thermophotovoltaics generate electrical power by thermal radiation between a hot emitter and a photovoltaic cell separated by a nanometer gap. This new technology exploits the properties of near-field radiative heat transfer at the nanoscale, which surpasses the efficiency limits of macroscopic objects. However, its use in engineered devices requires designer nanostructured materials to control the near-field radiative heat transfer, and the design of these materials is limited by the lack of a reliable, accurate computational models. This project seeks to advance computational modeling of near-field radiative heat transfer to enable novel devices for waste heat recovery and energy conversion. To ensure wide dissemination of the project outcomes, the computational framework will be made freely available to the public. K-12 outreach will be performed with a kit demonstrating the importance of thermophotovoltaic energy conversion.
The goal of this project is to conceive, implement and validate a comprehensive computational framework enabling multi-scale, many-body near-field radiative heat transfer simulations between complex micro/nanostructured materials. The computational framework is based on the numerically exact thermal discrete dipole approximation. The current implementation of the thermal discrete dipole approximation is however computationally expensive, as it requires solution of a large stochastic system of equations, and is thus limited to simulations involving two or three micro/nanosized objects and a surface. The project will address this bottleneck via a novel, computationally efficient version of the thermal discrete dipole approximation based on system Green?s functions that do not require solving a stochastic system of equations. Specifically, the goal of this project will be fulfilled by accomplishing three tasks: (1) Implementation of the thermal discrete dipole approximation based on system Green?s functions for multi-scale, many-body simulations of near-field radiative heat transfer; (2) Determination of the limit of applicability of the effective medium theory; (3) Validation of the computational framework via near-field radiative heat transfer experiments with devices made of micro/nanostructured materials. The project will fill a critical knowledge gap in near-field radiative heat transfer of micro/nanostructured materials that is heavily based on the effective medium theory at present. The outcome of the project will potentially accelerate the implementation of novel energy conversion and waste heat recovery technologies.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
