Thermo photovoltaics
Germanium substrates are also successfully used in thermo photovoltaic (TPV) devices, which have a photo response in the near infrared. And industrial heat source, like a furnace, typically emits in that wavelength region. TPV systems are used to recuperate part of this otherwise wasted heat energy. Its low band-gap, availability and cost-effectiveness make germanium the substrate of choice for this application. Moreover, record efficiency germanium based TPV cells have been realized using low-cost production processes, like screen-printing and dopant spinning.