The operating conditions of conventional multijunction solar cells are severely limited by the current matching requirements of serially connected devices. The goal of this SBIR program is to enhance the operating tolerance of high efficiency III-V solar cells by employing nanostructured materials in an advanced device design. By using quantum wells and quantum dots embedded in a higher band gap barrier material, solar cell devices that avoid the limitations of current matching can be constructed. This Phase I effort will focus on quantifying the trade-offs between short circuit current and open circuit voltage in InGaP / InGaAs nanostructures. Ultimately, the technical approach employed in this program has the potential of achieving conversion efficiencies exceeding 50% with a single p-n junction device, enabling improved overall performance and lower manufacturing costs than existing technologies.