Abstract: A heterostructure that includes, successively, a support substrate of a material having an electrical resistivity of less than 10?3 ohm·cm and a thermal conductivity of greater than 100 W·m?1·K?1, a bonding layer, a first seed layer of a monocrystalline material of composition AlxInyGa(1-x-y)N, a second seed layer of a monocrystalline material of composition AlxInyGa(1-x-y)N, and an active layer of a monocrystalline material of composition AlxInyGa(1-x-y)N, and being present in a thickness of between 3 and 100 micrometers. The materials of the support substrate, the bonding layer and the first seed layer are refractory at a temperature of greater than 750° C., the active layer and second seed layer have a difference in lattice parameter of less than 0.005 ?, the active layer is crack-free, and the heterostructure has a specific contact resistance between the bonding layer and the first seed layer that is less than or equal to 0.1 ohm·cm2.

Abstract: A heterostructure that includes, successively, a support substrate of a material having an electrical resistivity of less than 10?3 ohm·cm and a thermal conductivity of greater than 100 W·m?1·K?1, a bonding layer, a first seed layer of a monocrystalline material of composition AlxInyGa(1-x-y)N, a second seed layer of a monocrystalline material of composition AlxInyGa(1-x-y)N, and an active layer of a monocrystalline material of composition AlxInyGa(1-x-y)N, and being present in a thickness of between 3 and 100 micrometers. The materials of the support substrate, the bonding layer and the first seed layer are refractory at a temperature of greater than 750° C., the active layer and second seed layer have a difference in lattice parameter of less than 0.005 ?, the active layer is crack-free, and the heterostructure has a specific contact resistance between the bonding layer and the first seed layer that is less than or equal to 0.1 ohm·cm2.