Structure and Properties of Ab-initio Predicted B_xAl_1−xN Alloys

Ultra-wide band gap (UWBG) materials offer a promising avenue for the future of power electronics. Devices made from UWBG materials can operate at much higher voltages, frequencies, and temperatures than the current silicon devices, and could miniaturize the current electrical power conversion systems. Device performance is strongly correlated with the band gap of the material. Thus UWBG materials with large band gaps such as aluminum nitride and boron nitride, in addition to their high thermal conductivity and mechanical strength, could revolutionize power electronics. This study investigates the structure of BAlN and its band gap energy over a range of boron molar fractions. Formation energies were used as a basis for fitting a cluster expansion for B_xAl_1−xN structures and used to predict ground state structures over a range of boron concentration. A novel high-throughput workflow was utilized to calculate band structures for the ground state structures using DFT and GW methods. Band gap energies, impact ionization rates, and effective masses were also calculated for the ground state structures.