Nickel, N.H.; Gluba, M.A.: Properties of nitrogen molecules in ZnO. Journal of Electronic Materials 40 (2011), p. 440-445
DOI version (server of publisher)
For ZnO the use of nitrogen has been suggested to achieve p-type doping. Unfortunately, the doping efficiency is rather low. One cause can be the formation of N2 molecules that are widely believed to be inert. Here, we show that molecular nitrogen can cause defects in the ZnO lattice with localized states in the band gap either by forming an N2O molecule or by breaking a Zn-O bond without forming a chemical bond with the host lattice. Interestingly, bond breaking is energetically more favorable. This hitherto unexpected behavior of nitrogen molecules is also observed in other compound semiconductors.