Abstract
We present the band structure calculation of dilute-As GaNAs alloys (from 0% to 6.25% As) by employing the density-functional theory that adopts the local density approximation. Our studies indicate that the GaNAs shows a direct bandgap property. A small incorporation of As into the GaN alloy leads to the a significant decrease in the energy gap, which allows direct band gap transition covering from 3.47 eV (0% As) down to 1.93eV (6.25% As). The finding implies the dilute-As GaNAs alloy as an excellent candidate for the active material for optoelectronics that covers the entire visible spectral regime. The carrier effective masses of dilute-As GaNAs alloys are also presented.