The Role of Alloying Effects in the Formation of Electronic Structure of Unordered Group III Nitride Solid Solutions

Abstract

The effect of compositional and positional disorder on electronic properties of (Group III)-nitride solid solutions with the wurtzite structure was studied by the method of a model empirical pseudopotential using 32-atom supercells. The calculated values of the band-gap bowing parameter are found to be equal to 0.44, 2.72, and 4.16 for AlGaN, InGaN, InAIN, respectively. It is shown that the major contribution to the band-gap bowing parameter is made by the compositional disorder, whereas the bond-length relaxation reduces the effect of compositional disorder and the effects of the volume deformation. © 2004 MAIK "Nauka/Interperiodica".