The characteristics of MBE-grown InxAl1-xN/GaN surface states

The density and energy distribution of InxAl1-xN/GaN surface donor states are studied for InxAl1-xN structures with varying indium compositions. The results support a surface states model with a constant energy distribution of 2.17-2.63 eV below the conduction band minimum and a concentration of 4.64-8.27 x 10(13) cm(-2) eV(-1). It is shown that the properties of the surface states are affected by the surface indium composition x(s), as opposed to the bulk composition, x(b) (InxAl1-xN). Higher surface indium composition x(s) increases the density of surface states and narrows their energy distribution. Published by AIP Publishing.