BInGaN alloys lattice-matched to GaN for high-power high-efficiency visible LEDs

InGaN-based visible LEDs are used commercially for solid-state lighting and displays, but lattice mismatch with GaN limits the thickness of high crystalline quality InGaN quantum wells. Since narrower wells operate at a higher carrier density for a given current, more carriers are lost to Auger recombination and lower the LED efficiency. Alloying InGaN with boron, a smaller group-III element, is a promising method to create nitride alloys lattice-matched to GaN with band gaps in the visible range. In this work, we apply calculations based on hybrid density functional theory to predict the structural, electronic, and thermodynamic properties of BInGaN alloys. Our results show that BInGaN alloys with a B:In ratio of 2:3 are better lattice matched to GaN compared to InGaN. Varying the Ga mole fraction while keeping the B:In ratio constant enables the adjustment of the (direct) gap in the 1.75-3.39 eV range, which covers the entire visible spectrum. Our results indicate that BInGaN alloys are promising for fabricating nitride heterostructures with thick active regions for high-power, high-efficiency LEDs (article in press in Appl. Phys. Lett.).