Abstract: The invention concerns a monocrystalline coating crack-free coating of gallium nitride or mixed gallium nitride and another metal, on a substrate likely to cause extensive stresses in the coating, said substrate being coated with a buffer layer, wherein: at least a monocrystalline layer of a material having a thickness ranging between 100 and 300 nm, preferably between 200 and 250 nm, and whereof crystal lattice parameter is less than the crystal lattice parameter of the gallium nitride or of the mixed gallium nitride with another metal, is inserted in the coating of gallium nitride or mixed gallium nitride with another metal. The invention also concerns the method for preparing said coating. The invention further concerns electronic and optoelectronic devices comprising said coating.

Abstract: The invention concerns a monocrystalline coating crack-free coating of gallium nitride or mixed gallium nitride and another metal, on a substrate likely to cause extensive stresses in the coating, said substrate being coated with a buffer layer, wherein: at least a monocrystalline layer of a material having a thickness ranging between 100 and 300 nm, preferably between 200 and 250 nm, and whereof crystal lattice parameter is less than the crystal lattice parameter of the gallium nitride or of the mixed gallium nitride with another metal, is inserted in the coating of gallium nitride or mixed gallium nitride with another metal. The invention also concerns the method for preparing said coating. The invention further concerns electronic and optoelectronic devices comprising said coating.

Abstract: The invention concerns a monocrystalline coating crack-free coating of gallium nitride or mixed gallium nitride and another metal, on a substrate likely to cause extensive stresses in the coating, said substrate being coated with a buffer layer, wherein: at least a monocrystalline layer of a material having a thickness ranging between 100 and 300 nm, preferably between 200 and 250 nm, and whereof crystal lattice parameter is less than the crystal lattice parameter of the gallium nitride or of the mixed gallium nitride with another metal, is inserted in the coating of gallium nitride or mixed gallium nitride with another metal. The invention also concerns the method for preparing said coating. The invention further concerns electronic and optoelectronic devices comprising said coating.

Abstract: The invention concerns a monocrystalline coating crack-free coating of gallium nitride or mixed gallium nitride and another metal, on a substrate likely to cause extensive stresses in the coating, said substrate being coated with a buffer layer, wherein: at least a monocrystalline layer of a material having a thickness ranging between 100 and 300 nm, preferably between 200 and 250 nm, and whereof crystal lattice parameter is less than the crystal lattice parameter of the gallium nitride or of the mixed gallium nitride with another metal, is inserted in the coating of gallium nitride or mixed gallium nitride with another metal. The invention also concerns the method for preparing said coating. The invention further concerns electronic and optoelectronic devices comprising said coating.

Abstract: The heterojunction transistor comprises III-V semiconductor materials with a broad forbidden band material and a narrow forbidden band material. The narrow forbidden band material is an III-V compound containing gallium as one of its III elements and both arsenic and nitrogen as V elements, the nitrogen content being less than about 5%, and the narrow forbidden band material includes at least a fourth III or V element. Adding this fourth element makes it possible to adjust the width of the forbidden band, the conduction band discontinuity &Dgr;Ec, and the valance band discontinuity &Dgr;Ev of the heterojunction. The invention is applicable to making field effect transistors of the HEMT type having a very small forbidden band, and thus having high drain current. It also applies to making heterojunction bipolar transistors of small VBE, and thus capable of operating with power supply voltages that are very low.