SOLESTIAL, INC. — Department of Defense SBIR Phase I: AF181-040

Description

Reducing degradation of solar arrays is critically important for Orbital Transfer Elements (OTE). Currently used III-V solar cells suffer from radiation induced degradation.In this project we propose novel ultrathin bifacial silicon solar cells for OTE, which are rad-hard, enabling low degradation, and reducing the cost both in $/W and $/kg by a factor of 10 compared to III-V cells.Ultrathin bifacial silicon solar cells can deliver 28% cumulative efficiency, comparable to best-in-class III-V tandems. Ultrathin cells have necessary flexibility for solar arrays ROSA, Megaflex. This project will investigate and improve the radiation hardness of the ultrathin cell technology for the OTE/Van Allen belts radiation environment.Phase I will investigate and mitigate degradation mechanisms of silicon cells under electrons irradiation, develop cell design to achieve <20% degradation for OTE environment. The solar cells will be fabricated and characterized pre- and post-electron irradiation. The collaboration with SolAero Technologies will ensure industrial quality technology, characterization and testing.In Phase II, solar cell prototypes will be fabricated/integrated into mini-arrays for extensive reliability and radiation hardness testing to be suitable for OTE. The target parameters of the array will be achieved and a manufacturing technology for ultrathin bifacial silicon solar cells will be finalized.