Surface-assisted defect engineering of point defects in ZnO

Semiconductor surfaces facilitate the injection of highly mobile point defects into the underlying bulk, thereby offering a special means to manipulate bulk defect concentrations. The present work combines diffusion experiments and first-principles calculations for polar ZnO (0001) surface to demonstrate such manipulation. The rate behavior of oxygen interstitial injection varies dramatically between the Zn- and O-terminated ZnO surfaces. A specific injection pathway for the Zn-terminated surface is identified, and activation barrier determined from the first-principles calculations agrees closely with the experimental activation energy of 1.7 eV.