Journal of Physics D, Applied Physics vol:40 issue:6 pages:1807-1810
Nominally undoped and N-doped ZnO thin films were grown by plasma-assisted metalorganic chemical vapour deposition. P-type conductivity was confirmed by Hall-effect measurements, not only in the N-doped but also in the nominally undoped ZnO. The zinc vacancy and extrinsic nitrogen acceptor states were identified by low-temperature photoluminescence, with the energy level located at 270 meV and 180 meV above the valence-band maximum, respectively. An evident increment in the oxygen as well as nitrogen concentration in the p-type ZnO : N layer was well confirmed by secondary ion mass spectroscopy.