Spinel substrate and heteroepitaxial growth of III-V materials thereon

A method of forming a spinel composition having a monocrystalline lattice, comprising the steps of:

• a) forming a melt that includes magnesium, aluminum and oxygen, an element α that is a divalent cation having an ionic radius greater than divalent magnesium wherein the molar ratio of magnesium:α:aluminum:oxygen is (1−w):w:x:z, where w is greater than 0 and less than about 1, x is greater than about 2 and less than about 8, and z is equal to or greater than about 4 and equal to or less than about 13;
• b) immersing a spinel seed crystal in the melt;
• and
• c) rotating the seed crystal at a rate in a range of between about 2 and about 12 revolutions per minute, while withdrawing the seed crystal from the melt at a rate in a range of between about 1.00 mm per hour and about 2.54 mm per hour to form thereby said monocrystalline lattice.

A method of forming a composite, comprising the steps of:

• a) forming a melt that includes magnesium, aluminum and oxygen, an element α that is a divalent cation having an ionic radius greater than divalent magnesium wherein the molar ratio of magnesium:α :aluminum:oxygen is (1−w):w:x:z, where w is greater than 0 and less than about 1, x is greater than about 2 and less than about 8, and z is equal to or greater than about 4 and equal to or less than about 13;
• b) immersing a spinel seed crystal in the melt;
• c) rotating the seed crystal at a rate in a range of between about 2 and about 12 revolutions per minute, while withdrawing the seed crystal from the melt at a rate in a range of between about 1.00 mm per hour and about 2.54 mm per hour to form thereby said monocrystalline lattice;
• and
• d) depositing a III-V lattice layer on a surface of the monocrystalline lattice, said III-V lattice layer including a crystalline lattice of a nitride of at least one element selected from the group consisting of Group III and Group V elements of the Periodic Table of Elements, thereby forming said composite.