Periodic boundary quantum chemical study on ZnO ultra-violet laser emitting materials

Periodic density functional calculations have been carried out to study the surface structure and polarity of ZnO and also for the band gap modulation of ZnO by doping with various metals such as Be, Mg, Ca, Sr and Co. Our calculations reveal that the relaxation energy for the [000 (1) over bar] O surface is higher than that of the [0001] Zn surface and hence the O-terminated surface can be easily reconstructed. The charge distribution analysis shows that the Zn atoms in the [0001] Zn surface are more metallic and hence this surface cannot form a stable structure. The calculations for the band gap modulation of ZnO suggest that Mg doping is effective for obtaining a wide band gap with a stable structure.