Atomic displacement threshold energies and defect generation in GaN, AlN, and AlGaN: A high-throughput molecular dynamics investigation

Abstract

Gallium nitride, aluminum nitride, and their ternary alloys form an important class of wide-bandgap semiconductors employed in a variety of applications, including radiation-hard electronics. To better understand the effects of irradiation in these materials, molecular dynamics simulations were employed to determine the threshold recoil energies to permanently displace atoms from crystalline sites. Threshold displacement energies were calculated with the lattices at 0 K. Thermal effects are found to lower the threshold energies by ∼1 eV. The threshold energy knockout events observed result in Frenkel pair defects. The electronic structure and dynamics of these Frenkel pair defects are analyzed and the consequences for device operation are discussed.