Epitaxial ZnO thin films grown by pulsed electron beam deposition

Abstract: In this work, the pulsed electron beam deposition method (PED) is evaluated by studying the properties of ZnO thin films grown on c-cut sapphire substrates. The film composition, structure and surface morphology were investigated by means of Rutherford backscattering spectrometry, X-ray diffraction and atomic force microscopy. Optical absorption, resistivity and Hall effect measurements were performed in order to obtain the optical and electronic properties of the ZnO films. By a fine tuning of the deposition conditions, smooth, dense, stoichiometric and textured hexagonal ZnO films were epitaxially grown on (0001) sapphire at 700°C with a 30° rotation of the ZnO basal plane with respect to the sapphire substrate. The average transmittance of the films reaches 90% in the visible range with an optical band gap of 3.28eV. Electrical characterization reveals a high density of charge carrier of 3.4×1019 cm−3 along with a mobility of 11.53cm²/Vs. The electrical and optical properties are discussed and compared to ZnO thin films prepared by the similar and most well-known pulsed laser deposition method. [Copyright &y& Elsevier]