American private aerospace manufacturer and small satellite launch service provider Rocket Lab recently showcased its latest solar cell at a conversion efficiency of 33.3% that is scheduled for commercial operation later this year.
Rocket Lab acquired space solar cell manufacturer Solaero at the end of 2021, and the new IMM-β is also based on the IMM (Inverted Metamorphic Multi-junction) solar cells of Solaero, for which the material comes from InGaP and GaAs that makes it a III-V solar cell with a relatively good efficiency.
Rocket Lab believes that IMM-β solar cell is likely to become the space solar cell technology with the highest efficiency among commercial and mass production-capable space solar cells on the market, since its conversion efficiency of 33.3% has already exceeded IMM-α, currently under mass production, at 32%.
IMM-α solar itself exerts excellent performance. According to Solaero’s website, IMM-α solar cells are measured at 150μm in thickness, and are 42% lighter in mass compared to the traditional multi-junction space-grade solar cells at 49mg/cm².
The price of the new solar cell is bound to be exorbitant as it targets the aerospace field, though it can also be applied on private, military, and commercial markets. As pointed out by Rocket Lab, IMM-β is an anti-radiation solar cell at the same time, and is left with a power factor of 87% if exposed under 1-MeV (equivalence of losing 15 years of lifespan) with an implantation flux of 1E15 e/cm².
Rocket Lab commented that it is currently conducting the final space qualification test, and expects to initiate commercial operation for these cells later this year.
Solaero CEO Brad Clevenger commented that the research team is currently working with the Air Force Research Laboratory in the hopes of commercializing a space solar cell that contains the highest efficiency and the lightest weight, which means that the IMM solar cell, equipped with the largest cost competitiveness, can be commercialized at the same time.
The factory of Solaero is currently situated at Albuquerque of New Mexico, which occupies 11K m2 of land, and manufactures multiple space solar cells of various sizes.
(Cover photo source: Rocket Lab)