Homoepitaxial ZnO Thin Films Fabricated by Using Pulsed-Laser Deposition

ZnO thin films were deposited homoepitaxially by using pulsed-laser deposition on ZnO wafers grown by using the hydrothermal method. The dominant shallow donor level in the nominally undoped thin films is AlZn, as suggested by thermal admittance spectroscopy and low temperature photoluminescence measurements. The homoepitaxial ZnO:P thin films are n-conducting in the as-grown state, which facilitates investigations by Hall effect measurements. The Hall mobility of such ZnO:P thin films is higher than that of heteroepitaxial ZnO thin films and its temperature dependence is similar to that of ZnO single crystals grown by seeded chemical vapor transport.