On the electronic properties of two-dimensional honeycomb GaInN and GaAlN alloys: a molecular analysis

We have performed first principles total energy calculations to investigate the structural and the electronic properties of two-dimensional honeycomb GaAlN and GaInN alloys. Calculations were done using a coronene-like (C(24)H(12)) cluster and for different numbers of Ga, Al, and In atoms. The exchange and correlation potential energies were treated within the generalized gradient approximation (GGA). The bond length, dipole moment, binding energy, and gap between the HOMO and the LUMO are reported as a function of x. The stability of the structures depends on the site of the substituted atom; for example, when three Ga atoms are substituted, the GaInN alloy becomes unstable. The gap in the GaAlN increases from 3.76 eV (GaN) to 4.51 eV (AlN), and in the GaInN decreases to 2.11 eV. The biggest polarity occurs when eight and four Ga atoms are substituted, for GaAlN and GaInN, respectively.