This proposal describes a program to explore the feasibility of using InGaN alloy materials to form individual subcells in a multijunction solar cell. The InGaN compounds cover a wide range of bandgaps, able to be combined to cover most of the solar spectrum. They have shown increased radiation hardness, an important consideration for operating in the space environment. In Phase I, we will investigate their photovoltaic (PV) properties, which have not been reported. Blue Photonics, Inc. will prepare PV devices, using MOCVD growth, and will evaluate their properties. Lawrence Berkeley National Laboratories will provide their extensive knowledge of these compounds to define suitable growth conditions, along with characterization of the important material properties