NOVELTY - A support (A1) comprises a support substrate (10) including a bonding layer (2); and a monocrystalline seed layer (3) on the bonding layer made of a material and having properties to facilitate epitaxial growth of an active layer (4) of aluminum indium gallium nitride compound, where the seed layer and bonding layer comprise materials that provide a specific contact resistance between the seed layer and bonding layer of less than or equal to 0.1 ohm.cm-2, and the support substrate, bonding layer and the seed layer each comprises a material that is refractory at a temperature of greater than 750 degrees C.    USE - As support for the epitaxial growth of a layer of a material; for producing heterostructure for the manufacture of electronic power components, optoelectronic components or photovoltaic components (claimed) e.g. bipolar transistors, laser, solar cells.    ADVANTAGE - The support enables and facilitates the epitaxial growth of an active layer of a material without forming cracks. The heterostructure presents a sufficient vertical electrical conductivity for the intended applications such as the operation of Schottky diodes. The heterostructure can resist epitaxy temperatures of the active layer without deteriorating the materials or their electrical and thermal properties and thus enables operation of devices equivalent to devices formed from a bulk III/N material. The material of the seed layer and its level of doping prevent constituting an electrical conduction barrier between the active layer and the support substrate of the final heterostructure.    DETAILED DESCRIPTION - A support (A1) comprises a support substrate (10) including a bonding layer (2); a monocrystalline seed layer on the bonding layer (3) made of a material and having properties to facilitate epitaxial growth of an active layer (4) of aluminum indium gallium nitride compound of formula AlxInyGa(1-x-y)N, where the seed layer and bonding layer comprise materials that provide a specific contact resistance between the seed layer and bonding layer of less than or equal to 0.1 ohm.cm-2, and the support substrate, the bonding layer and the seed layer each comprises a material that is refractory at a temperature of greater than 750 degrees C.    x and y=0-1;or    x+y= less than or equal to 1.    INDEPENDENT CLAIMS are included for the following:    (1) a heterostructure comprising the support (A1), where the material of seed layer is of formula AlxInyGa(1-x-y)N, and an active layer expitaxially grown on the seed layer is crack-free and is made of a material having a composition of formula AlxInyGa(1-x-y)N, with a thickness of 3-100 micrometers and a dislocation density of less than 108 cm-2;    (2) an electronic power, optoelectronic or photovoltaic component formed in or on the active layer of a heterostructure comprising at least one electrical contact on the active layer and at least one electrical contact on the support substrate; and    (3) manufacturing (M1) a support for the epitaxy of a layer of material involving forming a bonding layer upon one of a donor substrate and/or a support substrate, bonding the donor substrate to the support substrate such that the bonding layer is situated between the donor substrate and the support substrate at an interface, and removing a portion of the donor substrate to leave a seed layer on the support substrate for epitaxial growth of an active layer, where the donor substrate, the support substrate and the bonding layer are refractory materials having a temperature of greater than 750 degrees C or greater than 1000 degrees C and chosen to provide a specific contact resistance between the seed layer and the bonding layer of less than or equal to 0.1 ohm.cm-2.    DESCRIPTION OF DRAWING(S) - The figure shows a view of the electronic power component formed on a heterostructure    Bonding layer (2)    Seed layer (3)    Active layer (4)    Support substrate (10)    Metallic layer. (100)