Thermophotovoltaic Cells: Converting Thermal Radiation into Electricity

A thermophotovoltaic (TPV) cell is a semiconductor device that converts radiation emitted by a hot source into electricity through the photovoltaic effect. Absorbed photons generate electron–hole pairs, which are separated by the cell’s internal electric field to deliver direct-current power to an external load. TPV cells are designed for the emission spectrum of a thermal source, typically dominated by infrared radiation.

A TPV system typically combines a heat source, thermal emitter, spectral-control components, photovoltaic cells, and cooling. Matching the emission spectrum to the cell’s bandgap improves energy utilization. Reflecting unusable low-energy photons back to the emitter further reduces losses. Performance depends on emitter temperature, cell temperature, and optical coupling. With solid-state conversion and no moving parts in the conversion core, TPV technology offers a modular approach to high-temperature waste heat recovery, thermal energy storage, and solar thermal power generation. In thermal storage systems, electricity is stored as high-temperature heat and converted back into electrical power on demand.