Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

Sb-doped ZnO films were fabricated on c-plane sapphire using the pulsed laser deposition method and characterized by the Hall effect measurement, X-ray photoelectron spectroscopy, X-ray diffraction, photoluminescence and positron annihilation spectroscopy. Systematic studies on the growth conditions with different Sb composition, oxygen pressure and post-growth annealing were conducted. If the Sb doping concentration is lower than the threshold ~8×E20 cm-3, the as-grown films grown with appropriate oxygen pressure could be n~4×E20 cm-3. The shallow donor was attributed to the SbZn related defect. Annealing these samples lead to the formation of the SbZn-2VZn shallow acceptor which subsequently compensated the free carrier. For samples with Sb concentration exceeding the threshold, the yielded as-grown samples were highly resistive. X-ray diffraction results showed that the Sb dopant occupied the O site rather than the Zn site as the Sb doping exceeded the threshold, whereas the SbO related deep acceptor was responsible for the high resistivity of the samples.