Defects and acceptor centers in ZnO introduced by C+-implantation

• DOI: 10.1007/s10853-013-7886-4
• Publication Date: 2013-11-26T11:12:45Z
• Authors: M. Jiang; X. D. Xue; Z. Q. Chen; Y. D. Liu; H. W. Liang; H. J. Zhang; A. Kawasuso
• Keywords: 0103 physical sciences; 01 natural sciences

ZnO single crystals were implanted with 280 keV C+ to a dose of 6 × 1016 cm−2. Positron annihilation measurements reveal a large number of vacancy clusters in the implanted sample. They further agglomerate into larger size or even microvoids after annealing up to 700 °C, and are fully removed at 1200 °C. X-ray diffraction, photoluminescence, and Raman scattering measurements all indicate severe damage introduced by implantation, and the damaged lattice is partially recovered after annealing above 500 °C. From room temperature photoluminescence measurements, an additional peak at around 3.235 eV appears in the implanted sample after annealing at 1100 °C, which is much stronger than that of the free exciton. From the analysis of low temperature photoluminescence spectra, this peak is mostly a free electron to acceptor (e,A0) line which is probably associated with C O .