On ternary nitride substrates for visible semiconductor light-emitters

Abstract

No nitride or other substrate material exists for growing lattice-matched nitride device structures. Use of bulk GaN or sapphire substrates is complicated by lattice and thermal mismatches that lead to defect and dislocation generation. To alleviate this problem, we recently proposed ternary nitride substrates on which lattice-matched structures could be grown for lasers within specified spectral bands. These proposed application-oriented nitride substrates have one drawback: several would be required to cover the visible spectrum. By taking advantage of the complex (but feature-rich) valence band structure of nitrides, we have determined that a single substrate (In0.15Ga0.85N) could be used for the development of efficient blue, green, and red laser diodes.