Our work to develop a scalable, high-power thermophotovoltaic device that can operate with low-temperature sources was just published in Advanced Materials! This involved the development of a process to create a nanogap (~150 nm) between an emitter and cell over a large area, as well as the development of a narrow-bandgap InAs-based PV cell. These components and processes should pave the way towards truly scalable, power-dense, and efficient solid-state heat engines that can work with a wide range of source temperatures. ETC Lab member Parth Solanki performed the modeling for this research, and collaborators from NREL include Jennifer Selvidge, Ryan France, John Goldsmith, and Myles Steiner.