Mechanism of Na-doped p-type ZnO films: Suppressing Na interstitials by codoping with H and Na of appropriate concentrations
Abstract
Hydrogen is codoped with sodium into ZnO films. X-ray photoelectron spectroscopy and secondary ion mass spectroscopy indicate that the Na concentration decreases as the substrate temperature increases. Hall-effect tests reveal a transition from n-type to p-type conduction when the growth temperature increases, which is explained by the suppression of Na interstitials by codoping with H and Na of appropriate concentrations. An insulating intended Na-H codoped sample shows reduced resistivity and p-type conductivity after annealing at 550 °C, which may be due to dissociation of NaZn-H complexes. The realization of p-type ZnO by Na-H codoping may explain the discrepancies in behavior of Na in ZnO and suggests the potential of Na-H codoping method [E.-C. Lee and K. J. Chang, Phys. Rev. B 70, 115210 (2004)].
- Publication:
-
Journal of Applied Physics
- Pub Date:
- November 2009
- DOI:
- 10.1063/1.3254221
- Bibcode:
- 2009JAP...106i3508L
- Keywords:
-
- annealing;
- doping profiles;
- electrical conductivity transitions;
- Hall effect;
- hydrogen;
- II-VI semiconductors;
- interstitials;
- secondary ion mass spectra;
- semiconductor doping;
- semiconductor thin films;
- sodium;
- wide band gap semiconductors;
- X-ray photoelectron spectra;
- zinc compounds;
- 61.72.uj;
- 61.72.sd;
- 79.60.Dp;
- 61.72.jj;
- 81.40.Ef;
- 73.61.Ga;
- 73.50.Jt;
- III-V and II-VI semiconductors;
- Impurity concentration;
- Adsorbed layers and thin films;
- Interstitials;
- Cold working work hardening;
- annealing post-deformation annealing quenching tempering recovery and crystallization;
- II-VI semiconductors;
- Galvanomagnetic and other magnetotransport effects