structure and stability of native defects and their complexes in zno: dft calculation

Zno is widely studied for several applications such as a photocatalyst, a working electrode for dye-sensitized solar cells and for thermoelectric devices. in this research, calculations based on density functional theory (dft) were done with a hubbard u correction to study pure zno and native defects in zno at low and high temperatures under oxygen-poor and -rich conditions, respectively. the formation energies of the native defects were calculated to identify the defects present under these different growth conditions. the native defects considered in this supercell included oxygen vacancies (znovo), interstitial oxygen (znooi), zinc vacancies (znovzn), and interstitial zinc (znozni), as well as defect complexes, such as znooivzn, znoznivo, znooizni, and znovozn. the calculated formation energies revealed that the growth environment affected the types of intrinsic defects formed in zno. the formation energies calculated showed that under oxygen-poor conditions, znovo and znozni were more likely defects while znovzn and znooi were more probable under oxygen-rich conditions.