Innovators at NASA’s Glenn Research Center have developed a low-cost, high-efficiency solar cell that uses a thin layer of selenium as the bonding material between wafers. Selenium is a semiconductor, and it is also transparent to light at photon energies below the band gap. The innovation allows a multi-junction solar cell to be developed without the constraint of lattice matching, and uses a low-cost, robust silicon wafer as the supporting bottom substrate and bottom cell. This enables a cell that is simultaneously lower in cost, more rugged, and more efficient than existing space solar cell designs. This technology has the potential to be used in next-generation solar cells in space, and it can be commercialized for terrestrial applications such as power plants and smart grid systems.

This innovation is a novel method for manufacturing a multi-junction photovoltaic (PV) cell using selenium as a bonding material sandwiched between two multi-junction wafers, enabling higher efficiencies. A multi-junction PV cell differs from a single junction cell in that it has multiple sub-cells (p-n junctions). A multi-junction cell can convert more of the Sun’s energy into electricity as the light passes through each layer. Glenn Research Center’s multi-junction PV cell has three junctions to improve efficiencies further, where the top wafer is comprised of high solar-energy absorbing materials forming a two-junction cell, and the bottom wafer would remain a simple silicon wafer substrate. The three-junction solar cell manufactured using selenium as the transparent interlayer has a higher efficiency than traditional multi-junction cells.

The technology has a 40% expected conversion efficiency. PV cells can be manufactured on a large scale, and have a low environmental impact (zero greenhouse gasses emitted). In addition, the rugged design can be used for both space and terrestrial applications.

This is an early-stage technology requiring additional development. Glenn welcomes co-development opportunities. Potential applications include utility-scale PV power plants, PV distributed generation (PV-DG) for smart grid systems, building-integrated photovoltaics (BIPV), building-applied photovoltaics (BAPV), government communications systems, military and space-based power systems, solar-powered aircraft, unmanned aerial vehicles (UAVs), and satellites.

NASA is actively seeking licensees to commercialize this technology. Please contact the Technology Transfer Office at This email address is being protected from spambots. You need JavaScript enabled to view it. to initiate licensing discussions. Follow this link for more information: .