Effect of O–O bonds on p-type conductivity in Ag-doped ZnO twin grain boundaries Project supported by the National Natural Science Foundation of China (Grant No. 11364009) and Natural Science Foundation of Guangxi Province, China (Grant No. 2014GXNSFFA118004). |
(color online) DOSs of bulk ZnO, GB7a, GB7b, GB7c and GB7d. The VBM of bulk ZnO is chosen to be zero in energy level. |