We are currently interested in studying the interplay of thermal, mechanical, optical, and electronic phenomena in novel custom-made micro and nano systems that will fulfill the following goals:
- Direct conversion of heat to electricity using thermal radiation at the nanoscale
- Ultra-precise infrared and THz light detection using extremely low loss mechanical resonators
- Ultra-precise vibration sensing using frequency tunable mechanical resonators
- Coherent thermal light sources using high temperature nanostructures
On-Chip Heat-to-Electricity Conversion
More than 50% of the energy consumed in industrialized is lost as waste heat and only a negligible (< 0.2%) fraction of this heat is converted back to electrical power. A portable heat-to-electricity conversion module that could be mounted directly on any hot surface would be an ideal solution for recycling this heat into electricity. Unfortunately, whereas large scale heat-to-electricity conversion technologies are mature, low cost and widely used (e.g., boiler, turbines), their smaller solid-state counterparts (e.g., thermoelectric generators) suffer from high cost and low efficiencies.
This project’s goal is to address the lack of efficient portable energy heat-to-electricity conversion technologies using a novel promising approach based the Near-Field Thermophotovoltaics (NFTPV) effect. The principle of this technology is to convert thermal light emitted by a heat source into electrical power using a specially tailored, low bandgap photovoltaic cell. For this process to reach appreciable performances, the distance between the hot side and the photovoltaic cell must be reduced to the sub-100 nm scale, such that the thermal radiation intensity is enhanced by near-field effects (see Figure 1). In this regime, heat could theoretically be converted to electrical power with much greater performance than using current thermoelectric generators.
Despite promising performances, there is still no experimental demonstration of NFTPV due to an important technical roadblock: the requirement of bringing parallel objects at sub-100 nm distances, while maintaining a large thermal gradient between them and avoiding contact.
This challenge was only recently overcome using a novel approach developed Prof. St-Gelais’ postdoctoral work at Cornell (see Figure 2). Our goal is now to integrate this distance control technology with an actual photovoltaic cell to implement the first demonstration of this exciting new technology.
Thermal Emission Control