Ultrawide bandgap semiconductor devices including magnesium germanium oxides
Various forms of Mg x Ge 1-x O 2-x are disclosed, where the Mg x Ge 1-x O 2-x are epitaxial layers formed on a substrate comprising a substantially single crystal substrate material. The epitaxial layer of Mg x Ge 1-x O 2-x has a crystal symmetry compatible with the substrate material. Semiconductor structures and devices comprising the epitaxial layer of Mg x Ge 1-x O 2-x are disclosed, along with methods of making the epitaxial layers and semiconductor structures and devices. Also disclosed is single crystal Mg x Ge 1-x O 2-x , with x having a value of 0≤x<1. The single crystal Mg x Ge 1-x O 2-x may comprise a dopant chosen from Ga, Al, Li + , N 3+ . The single crystal Mg x Ge 1-x O 2-x may comprise a p-type conductivity.
1. A composition of matter comprising single crystal Mg x Ge 1-x O 2-x , wherein 0<x<1, the single crystal Mg x Ge 1-x O 2-x comprising a dopant chosen from Ga, Al, Li + , N 3+ , or Ni + .
2. The composition of matter of claim 1 , wherein the single crystal Mg x Ge 1-x O 2-x comprises a cubic symmetry.
3. The composition of matter of claim 1 , wherein the dopant is Ga, and wherein the single crystal Mg x Ge 1-x O 2-x comprises a direct bandgap and a p-type conductivity.
4. The composition of matter of claim 3 , wherein the Ga dopant is located in a Ge site of a corresponding undoped Mg x Ge 1-x O 2-x crystal structure.
5. The composition of matter of claim 1 , wherein the dopant is Al, and wherein the single crystal Mg x Ge 1-x O 2-x comprises a direct bandgap and a p-type conductivity.
6. The composition of matter of claim 5 , wherein the Al dopant is located in a Ge site of a corresponding undoped Mg x Ge 1-x O 2-x crystal structure.
7. The composition of matter of claim 1 , wherein the dopant is Lit, and wherein the single crystal Mg x Ge 1-x O 2-x comprises a direct bandgap and a p-type conductivity.
8. The composition of matter of claim 7 , wherein the Li + dopant is located in a Ge site or a Mg site of a corresponding undoped Mg x Ge 1-x O 2-x crystal structure.
9. The composition of matter of claim 1 , wherein the dopant is N 3+ , and wherein the single crystal Mg x Ge 1-x O 2-x comprises a direct bandgap and a p-type conductivity.
10. The composition of matter of claim 9 , wherein the N 3+ dopant is located at an oxygen site of a corresponding undoped Mg x Ge 1-x O 2-x crystal structure.
11. The composition of matter of claim 1 , wherein the dopant is Ga, and wherein the single crystal Mg x Ge 1-x O 2-x comprises a direct bandgap and an n-type conductivity.
12. The composition of matter of claim 11 , wherein the Ga dopant is located in a Mg site of a corresponding undoped Mg x Ge 1-x O 2-x crystal structure.
13. The composition of matter of claim 1 , wherein the dopant is Al, and wherein the single crystal Mg x Ge 1-x O 2-x comprises a direct bandgap and an n-type conductivity.
14. The composition of matter of claim 13 , wherein the Al dopant is located in a Mg site of a corresponding undoped Mg x Ge 1-x O 2-x crystal structure.
15. The composition of matter of claim 1 , wherein the dopant is Ni + .
16. The composition of matter of claim 15 , wherein the Ni + dopant is located in a Mg site of a corresponding undoped Mg x Ge 1-x O 2-x crystal structure.
17. An epitaxial layer comprising the composition of matter of claim 1 .
18. A composition of matter comprising single crystal Mg x Ge 1-x O 2-x , with x having a value of 0<x<1, wherein the single crystal Mg x Ge 1-x O 2-x comprises a p-type conductivity.
19. The composition of matter of claim 18 , comprising a Ga dopant located in a Ge site of a corresponding undoped Mg x Ge 1-x O 2-x crystal structure.
20. The composition of matter of claim 18 , comprising an Al dopant located in a Ge site of a corresponding undoped Mg x Ge 1-x O 2-x crystal structure.
21. The composition of matter of claim 18 , comprising a Li + dopant located in a Ge site or a Mg site of a corresponding undoped Mg x Ge 1-x O 2-x crystal structure.
22. The composition of matter of claim 18 , comprising a N 3+ dopant located at an oxygen site of a corresponding undoped Mg x Ge 1-x O 2-x crystal structure.
23. The composition of matter of claim 18 , wherein:
a. the single crystal Mg x Ge 1-x O 2-x has a doped unit cell structure and a corresponding undoped unit cell structure;
b. with the doped unit cell structure, the single crystal Mg x Ge 1-x O 2-x is an indirect bandgap p-type material;
c. the doped unit cell structure comprises a Ge atom in a first location that is occupied by Mg in the corresponding undoped unit cell structure; and
d. the doped unit cell structure comprises a Mg atom in a second location that is occupied by Ge in the corresponding undoped unit cell structure.
24. The composition of matter of claim 23 , wherein in the doped unit cell structure, the Ge atom is octahedrally bonded and the Mg atom in the second location is tetrahedrally bonded.
25. An epitaxial layer comprising the composition of matter of claim 18 .