Thermophotovoltaik Generator
© Fraunhofer ISE
Wiederverstromung von in Form von Hochtemperaturwärme gespeicherter Energie mittels TPV Zellen.

Thermophotovoltaic Generator

The use of high temperature energy storage for power generation using thermophotovoltaic (TPV) cells.

Thermophotovoltaics

Analogous to solar cells, thermophotovoltaics (TPV) directly converts electromagnetic radiation to electrical energy.  Unlike solar cells, however, the radiation does not come from the sun but rather from a heated emitter in the form of thermal radiation (long-wave photons). Specially designed thermophotovoltaic cells made of absorber materials with bandgaps in the infrared range can efficiently convert thermal radiation into electricity.

In an energy system based on fluctuating renewable energy sources, thermophotovoltaic systems can make an important contribution. Excess electrical energy can be stored in the form of high-temperature heat. Upon demand the stored heat can be converted back to electricity using thermophotovoltaic modules. The high conversion efficiency of TPV cells is a decisive factor for the efficiency of the total conversion process (electric-to-electric). Also, smart photon management is essential: Mirrors integrated into the TPV cells reflect the photons, which have energy levels that are too low to be used in the photovoltaic process, back to the heated emitter to be recycled. Thus, higher system efficiencies are achieved.

At Fraunhofer ISE we develop customized low bandgap III-V absorber materials based on GaAs, InP, GaSb, and Ge as well as high transparency tunnel diodes. By means of a metamorphic buffer layer we realize engineered substrates based on GaAs in order to replace comparatively costly InP substrates.  We also develop thin film processes and highly reflective, electrically conductive back surface reflector layers for efficient photon management.  Finally, we offer our customers long-standing expertise in the development of dense array modules, including the packaging technology and the thermal management.

In addition, we are working on the optical modeling, the realization and the characterization of selective emitters for TPV systems. Through specially designed coatings, it is possible to generate resonance phenomena in surface structures and/or thin film systems so that they preferentially emit photons which can be used by the thermophotovoltaic cell.

Our R&D-Services on this Topic:

  • Development of epitaxy structures for TPV devices based on GaAs, InP, GaSb, and Ge
  • InP engineered substrates on GaAs
  • Thermophotovoltaic cell design optimization
  • Thin film processing and back surface reflector technology
  • Module development and packaging technology
  • Electrical characterization of TPV cells and modules
  • Reliability investigations
  • Modeling, realization and characterization of selective emitters

Selected Publications on Thermophotovoltaics

YEAR Title/Author Document Type
2019 Development of Back Side Technology for Light Trapping and Photon Recycling in GaAs Solar Cells
Micha, D.; Höhn, O.; Oliva, E.; Klinger, V.; Bett, A.; Dimroth, F.
Journal Article
2018 Combining photon recycling and concentrated illumination in a GaAs heterojunction solar cell
Schilling, C.; Höhn, O.; Micha, D.N.; Heckelmann, S.; Klinger, V.; Oliva, E.; Glunz, S.W.; Dimroth, F.
Journal Article
2012 Advanced Concepts in Concentrating Photovoltaic (CPV)
Wiesenfarth, M.; Helmers, H.; Philipps, S.P.; Steiner, M.; Bett, A.W.
Conference Paper
2012 Front-side interconnected large area concentrator cells for compact concentrator modules
Wiesenfarth, M.; Steiner, M.; Helmers, H.; Siefer, G.; Oliva, E.; Dimroth, F.; Shelef, G.; Polonsky, G.; Flitsanov, Y.; Kribus, A.; Bett, A.W.
Conference Paper
2008 Development, characterisation and 1000 suns outdoor tests of GaAs monolithic interconnected module (MIM) receivers
Löckenhoff, R.; Dimroth, F.; Oliva, E.; Ohm, A.; Wilde, J.; Faiman, D.; Biryukov, S.; Melnichak, V.; Kabalo, S.; Bokobza, D.; Bett, A.W.
Journal Article
2005 GaSb Based PV Modules for a TPV Generator System
Schlegl, T.; Abbott, P.; Aicher, T.; Dimroth, F.; Siefer, G.; Szolak, R.; Bett, A.W.
Conference Paper
2004 Development of a novel TPV power generator
Aicher, T.; Kästner, P.; Gopinath, A.; Gombert, A.; Bett, A.W.; Schlegl, T.; Hebling, C.; Luther, J.
Conference Paper
2003 Growth of Sb-based materials by MOVPE
Dimroth, F.; Agert, C.; Bett, A.W.
Journal Article
2003 GaSb photovoltaic cells for applications in TPV generators
Bett, A.W. and Sulima, O.V.
Journal Article
2001 Fabrication and Simulation of GaSb Thermophotovoltaic Cells
Sulima, O.V and Bett, A.W
Journal Article
2000 Radiation filters and emitters for the NIR based on periodically structured metal surfaces
Heinzel, A.; Boerner, V.; Gombert, A.; Bläsi, A.; Wittwer, V.; Luther, J.
Journal Article