Doping of ZnO by Group-IB Elements

The authors present their first-principles calculations of doping effects in ZnO with group-IB elements such as Cu, Ag, and Au. The calculated transition energies ε (0-) for substitutional Cu, Ag, and Au are 0.7, 0.4, and 0.5 eV, respectively. The calculated formation energies are very low for these group-IB elements on the substitutional sites, but rather high at the interstitial sites under oxygen-rich growth conditions. Under the conditions, the formation of major hole-killer defects, such as oxygen vacancies and Zn interstitial, are suppressed. Thus, Ag may be a good candidate for producing p -type ZnO.