(Ga, In)(N, As)-fine structure of the band gap due to nearest-neighbor configurations of the isovalent nitrogen - art. no. 121203

An intrinsic property of quaternary alloys A(1-y)B(y)C(1-x)D(x) (x approxim ate to 1 - 3 %) with D being an isovalent trap is reported: a set of discre te band gaps occurs due to substitution of the isovalent trap D on sites wi th different nearest-neighbor environments. Exemplary, this phenomenon is d emonstrated for (Ga, In)(N,As) by experiment and explained by tight-binding supercell calculations. The band gap of this nitrogen-poor alloy is bluesh ifted by simply moving the nitrogen isovalent traps from Ga-ligand rich sit es to In-ligand rich sites, without changing the alloy composition.