Theoretical study of stability and electronic structure of Li(Mg,Zn)N alloys: A candidate for solid state lighting

Using selective chemical mutation, we propose and investigate the electronic structure of an alloy with the potential to fill the green gap left open by existing InGaN based emission devices. The small mismatch between LiMgN and LiZnN, along with electronic band gaps spanning the visible range, makes them good candidates. Calculations are performed using a first-principles band structure method, with the special quasirandom structure approach employed to generate the random alloys. Comparison of LiMgN and LiZnN with their binary nitride analogs is made, and the energetic and electronic effects of alloy ordering are investigated. These alloys exhibit negative mixing enthalpies atypical of traditional binary nitride systems, which is explained in terms of the low lattice strain and the chemical bonding effects of the interstitial Li ions.