ZnO films grown on sapphire substrates are implanted with lO0-keV Li ions up to a total dose of 1 × 10^16 cm^-2. Vacancy-type defects, mostly vacancy dusters, are observed by positron annihilation measurements af...ZnO films grown on sapphire substrates are implanted with lO0-keV Li ions up to a total dose of 1 × 10^16 cm^-2. Vacancy-type defects, mostly vacancy dusters, are observed by positron annihilation measurements after implantation. Upon annealing, they first have an agglomeration process which leads to the growth in the vacancy size. After anneling at about 500℃, vacancy clusters grow into microvoids, which is indicated by the positronium formation. With annealing temperature increases to above 500℃, the microvoids begin to recover, and finMly M1 the implantation-induced vacancy defects are removed at 1000℃. No Li nanoclusters can be observed after Li^＋ implantation.展开更多
文摘ZnO films grown on sapphire substrates are implanted with lO0-keV Li ions up to a total dose of 1 × 10^16 cm^-2. Vacancy-type defects, mostly vacancy dusters, are observed by positron annihilation measurements after implantation. Upon annealing, they first have an agglomeration process which leads to the growth in the vacancy size. After anneling at about 500℃, vacancy clusters grow into microvoids, which is indicated by the positronium formation. With annealing temperature increases to above 500℃, the microvoids begin to recover, and finMly M1 the implantation-induced vacancy defects are removed at 1000℃. No Li nanoclusters can be observed after Li^＋ implantation.
