Researchers from Germany’s University of Potsdam and TU Berlin have proposed the possibility of using lunar regolith to make glass for solar cells and modules on the moon itself. This ‘promising approach,’ they believe, would enable the simple, scalable production of solar cells on the moon to supply future lunar habitats or even cities with energy.
In their study, the researchers propose that halide perovskite PV can be fabricated on regolith-based moonglass, which can be produced on the moon itself, thus saving 99% of material transport weight.
As per the study, “This enables effective specific power ratios, over 22–50 W/g, a factor of 20–100 higher compared to traditional space PV solutions, while not compromising radiation shielding, reliability, and mechanical stability as done until now.”
Lunar regolith is a mix of fine dust and broken rock on the moon, comprising mainly SiO2 (silicon dioxide or silica), Al2O3 (aluminum oxide) and CaO (calcium oxide).
According to the research team, this moonglass exhibits high tolerance to high-energetic proton irradiation, which, when combined with the radiation tolerance of perovskites, allows highly radiation-tolerant, reliable devices, paving the way for future sustainable lunar-energy solutions, according to the researchers.
Using real samples of lunar soil from the Apollo missions, the team produced a regolith simulant at TU Berlin, which can be melted to produce glass in light or dark colors. They fabricated halide perovskite cells on this moonglass.
“These solar cells require ultrathin absorber layers of 500 to 800 nanometers only, allowing the fabrication of 400 square meter solar cells with just one kilogram of perovskite raw material brought from Earth,” said Dr. Felix Lang of the University of Potsdam, who led the research.
According to the team, a small-scale production line with an equipment mass of around ∼3 tonnes, producing moonglass/perovskite solar cells on the Moon would outperform solutions fabricated on Earth above a PV capacity of 3 MW, roughly capable of supplying a base for ∼200 astronauts (extrapolating power requirements of the international space station).
Of the 3 device configurations attempted by the team, the power conversion efficiency reached 9.4% with the ultrathin metal contact, 12.1% with IZO under unoptimized conditions for the deposition of the contact layers, comparable to efficiencies achieved on normal glass substrates. They believe that further optimization of the transparent contact layers to reduce the series resistance of the devices could allow an efficiency of 17.5%.
“Combining high radiation tolerance, highest power-per-launched-mass ratios, and a facile fabrication, our regolith-based Moon-perovskite solar cells are the most promising route to power future Moon habitats in the near future,” stress the researchers.
Their research work titled Moon photovoltaics utilizing lunar regolith and halide perovskites was recently published in the journal Device and also mentioned in the Nature Research Highlights.
