Abstract: Binding energy, electronic structure and optical properties of pure AlN and Ag, S codoping AlN were calculated with first-principles ultrasoft pseudopotential approach of plane wave based upon density functional theory.It shows that concentration of doping Ag atoms can be increased in AlN and acceptor level becomes shallower by introduction of S atoms. Acceptor Ag atoms play an important role in activating. So Ag, S codoping AlN is expected as an efficient means of p-type doping.Imaginary part of dielectric function and optical absorption spectrum of the doping system show a new peak in low energy region.And absorption edge extends to low energy. Doping system enhances low frequency electromagnetic wave absorption.

Key words: first-principles, Ag-S codoped AlN, electronic structure, optical properties