Multijunction solar cell structures (100) including high quality epitaxial layers of monocrystalline semiconductor materials that are grown overlying monocrystalline substrates (102) such as large silicon wafers by forming a compliant substrate for growing the monocrystalline layers are disclosed. One way to achieve the formation of a compliant substrate includes first growing an accommodating buffer layer (104) on a silicon wafer. The accommodating buffer (104) layer is a layer of monocrystalline material spaced apart from the silicon wafer by an amorphous interface layer (112) of silicon oxide. The amorphous interface layer (112) dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. Multiple and varied accommodating buffer layers can be used to achieve the monolithic integration of multiple non-lattice matched solar cell junctions.