Near-Field Thermophotovoltaic Conversion with High Electrical Power Density and Cell Efficiency above 14.
A huge amount of thermal energy is available close to material surfaces in radiative and nonradiative states, which can be useful for matter characterization or energy harvesting. Even though a full class of novel nanoengineered devices has been predicted over the last two decades for exploiting near-field thermal photons, efficient near-field thermophotovoltaic conversion could not be achieved experimentally until now. Here, we realize a proof of principle by using a micrometer-sized indium antimonide photovoltaic cell cooled at 77 K and approached at nanometer distances from a hot (∼730 K) graphite microsphere emitter. We demonstrate a near-field power conversion efficiency of the cell above 14% and unprecedented electrical power density outputs (0.75 W cm-2), which are orders of magnitude larger than all previous attempts. These results highlight that near-field thermophotovoltaic converters are now competing with other thermal-to-electrical conversion devices and also pave the way for efficient photoelectric detection of near-field thermal photons.
['Lucchesi|Christophe|C|', 'Cakiroglu|Dilek|D|', 'Perez|Jean-Philippe|JP|', 'Taliercio|Thierry|T|', 'Tournié|Eric|E|https://orcid.org/0000-0002-8177-0810', 'Chapuis|Pierre-Olivier|PO|https://orcid.org/0000-0002-6264-2530', 'Vaillon|Rodolphe|R|https://orcid.org/0000-0002-8559-3604']
thermophotovoltaics conversion efficiency Thermal radiation nanoscale