Limitations to band gap tuning in nitride semiconductor alloys

Relations between the band gaps of nitride alloys and their lattice parameters are presented and limits to tuning of the fundamental gap in nitride semiconductors are set by combining a large number of experimental data with ab initio theoretical calculations. Large band gap bowings obtained theoretically for Ga(x)Al(1-x)N, In(x)Ga(1-x)N, and In(x)Al(1-x)N for uniform as well as clustered arrangements of the cation atoms are considered in the theoretical analysis. It is shown that indium plays a particular role in nitride alloys being responsible for most of the observed effects. (C) 2010 American Institute of Physics. [doi:10.1063/1.3357419]