TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The substrate system further comprises a upper layer of aluminum gallium nitride (I) disposed over the metamorphic transition region that comprises a superlattice. The layers of the material having the same general chemical composition as the substrate material generally decrease in thickness away from the substrate. The layer of the material having the same general chemical composition as the substrate material furthest from the substrate has thickness less than the critical thickness for formation of dislocations. The layers of aluminum gallium nitride (I) generally increase in thickness away from the substrate. The layer of aluminum gallium nitride (I) closest to the substrate has a thickness less than the critical thickness for formation of dislocations. The substrate and the upper layer of aluminum gallium nitride (I) have different crystal systems. The metamorphic transition region: contains threading dislocations, where the number density of the threading dislocations decreases along the growth direction; and has a lattice constant which, adjacent to the substrate, is substantially equal to the lattice constant of the substrate and which, adjacent to the upper layer of aluminum gallium nitride (I), is substantially equal to the lattice constant of the upper layer of aluminum gallium nitride (I). The upper layer of aluminum gallium nitride (I) contains fewer than 107, preferably fewer than 105 threading dislocations per cm2. The alternating layers contain many layers of: aluminum trioxide and the substrate material is sapphire; silicon and the substrate material is silicon; gallium arsenide and the substrate material is gallium arsenide; or silicon carbide and the substrate material is silicon carbide. Preferred Method: The method further comprises depositing a layer of aluminum gallium nitride (I) on the metamorphic transition region. The metamorphic transition region is deposited using metal organic vapor phase epitaxy, molecular beam epitaxy, atomic layer deposition, or sputtering or plasma deposition. EXAMPLE - No suitable example given.