Lattice Constant and Band Gap Tuning in BInGaN Alloys for Next-Generation LEDs*

InGaN light-emitting diodes (LEDs) have enabled significant energy and cost savings, and further savings can be realized by operating at the same efficiency at higher power. However, the efficiency of currently available InGaN LEDs is lowered by the loss of carriers to Auger recombination when operating at high power. The Auger loss can be reduced by increasing the active-region volume, but the lattice mismatch between thick InGaN active layers and underlying GaN layers cause performance-degrading dislocations. Previous work has shown that this problem can be addressed by co-alloying InGaN with BN. Doing so can produce alloys that maintain an approximate lattice match to GaN while allowing for a band gap that is adjustable throughout the visible range. In this work, we expand on previous hybrid density functional theory calculations to explore the thermodynamic, structural, and electronic properties of a larger area of the B_xIn_yGa_1-x-yN composition space and examine the wurtzite, zinc blende, and planar hexagonal phases. A more thorough understanding of these properties will help to direct efforts to fabricate thick active regions for more cost-effective BInGaN LEDs.