Significant improvements in photovoltaic materials and systems are required to enable future exploration missions. This SBIR project, involving two innovative organizations: CFD Research Corporation (CFDRC) and University of California Riverside (UCR), has two major objectives: 1) develop and provide reliable, validated computational tools for assessment, design, and optimization of novel nanostructures based on Quantum Dots (QD) for future nano-devices for space applications; 2) investigate, design, and demonstrate new photovoltaic (PV) structures based on QD nanotechnology, with improved efficiency and radiation hardness. The inherently radiation tolerant quantum dots of variable sizes maximize absorption of different light wavelengths ("multicolor" cell), which dramatically improves PV efficiency and diminishes the radiation-induced degradation. Phase I includes development of numerical tools for modeling electron-phonon transport in QD superlattices for photovoltaic applications, using experimental data from UCR Nano-Device Laboratory for validation and calibration of the new tools, and computational proof-of-concept. In Phase II, the new QD models will be integrated into CFDRC's advanced photonic-electronic device simulator. Novel QD photovoltaic nano-engineered materials and designs will be down-selected for further development to the point of testable prototypes. They will be fabricated and provided to NASA for electrical characterization and radiation testing.