Surface electronic properties of In-rich InGaN alloys grown by MOCVD

The band bending, position of Fermi level at the cleaned surfaces and bulk Fermi level of In-rich InxGa1-xN alloys grown by metal-organic chemical vapor deposition with a composition of 0.20 ≤ x ≤ 1.00 have been investigated using X-ray photoemission spectroscopy, infrared reflectivity and Hall effect measurements. Wet etching of InxGa1-xN alloys in HCl successfully reduced the native oxides at the surface, allowing these measurements to be performed more accurately. Electron accumulation layers, accompanied by downward band bending, are present at the surface, with a decrease to flatband conditions occurring at x ≈ 0.2 with increasing Ga fraction.