The hydrothermal growth of low carrier concentration ZnO at high water and hydrogen pressures

Abstract Hydrothermally grown Li doped ZnO crystals can be prepared with carrier concentrations as low as 5×10 14 cm −3 by Zn annealing followed by an air bake which out diffuses Li. Out diffusion of H in hydrogen doped crystals produced samples with carrier concentrations of about 5×10 15 . It appears that out diffusion of Li grown material can produce ZnO suitable for acousto-electric applications. A procedure for growth at high hydrogen pressures is described as is a procedure for growth at water pressures up to about 25,000 psi. At pressures of 25,000 psi rates as high as 29 mil/da have been obtained with quality comparable to ZnO grown under normal conditions. The dependence of growth rate on crystallographic direction is discussed.