ESA has supported the development and design of this flexible and ultra-thin solar cell to offer the best power-to-weight ratio for space missions. We hope that an advance that in the future will be transferred to commercial solar energy.
Just 0.02mm thick – thinner than a human hair – the prototype solar cells were developed by Azur Space Solar Power in Germany and tf2 in the Netherlands; the cell in the photo is tf2. The project was supported by the European Space Agency, which investigates new technologies for space.
With an efficiency of up to 32% at the end of life, the solar cells were produced using a technique called ” epitaxial peeling”, which means that they were shed from the germanium substrate layer on which they were initially placed, in so that the expensive material can be reused.
Triple and quad junction solar cells were manufactured. This means that they consist of three or four different layers of material, optimized to make use of the different wavelengths of light that make up the solar spectrum.
These thinner than paper solar cells could be harnessed for future ESA satellites or high altitude pseudo-satellites (HAPS) – unmanned airplanes or balloons to perform satellite-like tasks from the upper atmosphere.