III-V Solar Cells and Devices

Photo of the record solar cell
© Fraunhofer ISE
Photo of the record solar cell with an efficiency of 41.1% Sunlight is concentrated by a factor of 454 and focused onto a small 5mm² multi-junction solar cell made of Ga0.35In0.65P/Ga0.83In0.17As/Ge.
© Fraunhofer ISE
Solar cell technology in a class 100 clean room.

We develop solar cells from numerous III-V semiconductor materials. These solar cell structures are optimized for specific applications – such as satellites, PV concentrator systems and laser power beaming. As a result, we have structures capable of converting electromagnetic radiation in the wavelength range between 300 nm and 2000 nm into electrical energy, at an irradiance of anywhere between just a few milliwatts/cm² and several hundred watts/cm².

The semiconductor structures are fabricated epitaxially in our two MOVPE reactors and we have state-of-the-art clean room technology at our disposal for processing solar cells.
Solar cells can be characterized in the CalLab, Fraunhofer ISE’s calibration laboratory. In addition to developing new solar cell concepts, we can also provide clients with small quantities of customized devices.

Research focuses on the following areas:

  • GaAs single-junction solar cells for applications under one-sun illumination and under concentration
  • Triple-junction solar cells (lattice-matched and metamorphic)
  • III-V multi-junction solar cells with up to six sub-cells
  • Wafer-bonded multi-junction cells
  • Laser-power beaming devices
  • Monolithic interconnected modules (MIMs)
  • Growing III-V semiconductors on silicon
  • Solar cells for thermophotovoltaics (TPV)

Efficiencies reached:

44.7% @ 297 suns (GaInP/GaAs/GaInAsP/GaInAs quadruple-junction solar cell)
41.1% @ 450 suns (Ga 0.35 In 0.65 P/Ga 0.83 In 0.17 As/Ge triple-junction solar cell)
29.1% @ 117 suns (GaAs single-junction solar cell)
26.4% @ 1 sun (GaAs single-junction solar cell)

Selected publications on this topic (Fraunhofer-Publica database)