Group III/IV/V-assisted heteroepitaxial growth of II-(IV/V)-N optoelectronic semiconductors
Described herein are devices and methods for the heteroepitaxial growth of II-(I/V)-N optoelectronic semiconductors using enhanced growth parameters and isovalent substitution to include a group III, IV or V additive at some cation sites. The described growth conditions and additive lead to increased optoelectronic properties (e.g., resistivity, carrier mobility, carrier concentration and bandgap) as well as improved surface morphology (e.g., surface roughness, crystal structure).
1 . A device comprising:
a first cation selected from group II, a second cation selected from group IV or group V and a nitride anion;
an additive selected from group III, group IV or group V;
wherein the additive replaces a portion of the first cation, the second cation or both via isovalent substitution thereby improving surface morphology, optoelectronic properties, or both; and
wherein the device is an optoelectronic semiconductor.
2 . The device of claim 1 , wherein the additive is selected from Sn, Sb or Bi.
3 . The device of claim 1 , wherein the additive replaces a portion of the second cation.
4 . The device of claim 1 , wherein the device is grown on a sapphire substrate.
5 . The device of claim 4 , wherein the sapphire substrate has a c-plane (001) orientation.
6 . The device of claim 1 , wherein the device is grown at an elevated temperature greater than or equal to 100° C.
7 . The device of claim 1 , wherein the device has a reduced resistivity in comparison to a device without the additive, the sapphire substrate, the elevated temperature or a combination thereof.
8 . The device of claim 1 , wherein the device has a resistivity less than or equal to 1.0 Ω-cm.
9 . The device of claim 1 , wherein the device has a reduced bandgap in comparison to a device without the additive, the sapphire substrate, the elevated temperature or a combination thereof.
10 . The device of claim 1 , wherein the device has a bandgap selected from the range of 1.5 to 2.5 eV.
11 . The device of claim 1 , wherein the device has an increased carrier mobility in comparison to a device without the additive, the sapphire substrate, the elevated temperature or a combination thereof.
12 . The device of claim 1 , wherein the device has a carrier mobility greater than or equal to 0.02 cm 2 V −1 s −1 .
13 . The device of claim 1 , wherein the first cation is selected from Zn and Mg.
14 . The device of claim 1 , wherein the second cation is selected from Ti, Ge and Nb.
15 . The device of claim 1 , wherein the first cation comprises Zn and the second cation comprises Ti.
16 . A method comprising:
growing a semiconductor comprising a first cation selected from group II, a second cation selected from group IV or group V and a nitride anion on a sapphire substrate at a temperature greater than or equal to 100° C.;
substituting the first cation, the second cation or both with an additive selected from group III, group IV or group V.
17 . The method of claim 16 , wherein the additive is selected from Sn, Sb or Bi.
18 . The method of claim 16 , wherein the sapphire substrate has a c-plane (001) orientation.
19 . The method of claim 16 , wherein the first cation is selected from Zn and Mg.
20 . The method of claim 16 , wherein the second cation is selected from Ti, Ge and Nb.