While the absolute majority of works deal with physical techniques of thin film growth, a considerably smaller amount of papers describes doping of ZnO single crystal. Since performance of thin films is strongly dependent on their quality, which also tends to degrade with the introduction of dopants, a semiconductor single crystal would be a desirable object for investigation of electrical properties of the material. However, there are certain difficulties with obtaining single crystal of ZnO doped with group-V elements. Four methods are known for ZnO single crystal growth: hydrothermal, growth from the melt, vapor transport, and flux growth 20 among which hydrothermal growth is the most commonly applied. Incorporation of a dopant, which is essentially an impurity, poses additional obstacles to growth of quality single crystal. Thus, doping with group-V elements during hydrothermal growth is difficult as there are almost no compounds stable at the growth conditions containing those elements in a cation form while incorporation in an anion form is unlikely due to a strong competition with OH -ions in a basic medium. Another problem is incorporation of self-compensating hydrogen impurities during hydrothermal growth.