Electrical and optical properties of undoped p-type ZnO films

ZnO films were grown on Si(100) and quartz substrates by inductively coupled plasma assisted chemical vapor deposition (ICP-CVD), using metal organic DEZ (diethlyzinc), and a gas mixture of Ar and O-2. The process temperature ranged between room temperature and 400 degrees C. ZnO films showed both p- and n-type electrical properties according to the oxygen flow rates. By using inductively coupled plasma (ICP), promotion of dissociation and activation of oxygen gas was caused and solved the lack of oxygen in the films, which produced the native Zn vacancy. Consequently, the p-type electrical property of ZnO films was realized. From the Hall and resistivity measurements, the p-type ZnO films showed the resistivity in the range of 4.7 x 10(-3) and 9.7 x 10(-3) Omega cm. hole mobility and the concentration of the film ranged from 200 to 272 cm(2)/V.s and from 2.4 x 10(18) to 6.6 x 10(18) cm(-3). (C) 2008 Elsevier B.V. All rights reserved.