Abstract：The electronic and optical characteristics of wurtzite and metastable rock-salt ZnO were given comparative study based on the density function pseudopotential method.Calculation results show that the ionicity of metastable rock-salt ZnO decrease.The GGA energy band gap of metastable rock-salt ZnO is a little bigger than the one of wurtzite ZnO.The differences of electronic structure between the two polymorphs lead to the different optical characteristics.It is predicted that metastable rock-salt ZnO possesses the negative differential conduction, especially when it is heavily doped.The stronger electron-photon coupling and the wider optical response region in the metastable rock-salt ZnO, which makes it more suitable for optical applications especially in the extremely short-wave region, in spite of an indirect band gap characteristic.

Keyword：wurtzite ZnO;metastable rock-salt ZnO;electronic and optical properties;density;function pseudopotential method;