Compound semiconductor heterostructure (AlDGa2Se3-nSi) uses a new material for photovoltaic applications. This Metal-Semiconductor-Semiconductor (MS＇S) structure with Ga2Se3 as an intermediate layer has been proposed as a better alternative to conventional Metal-Insulator-Semiconductor (MIS) solar cells for normal illumination. It is shown here that in the whole range - starting from lower intensity, i.e. at a concentration ratio, C-r similar to 1, to very high illumination level, C-r similar to 2000, the proposed new structure gives better results than corresponding MIS solar cells.