Growth of non-polar a-plane Zn1-xCdxO films by pulsed laser deposition

Non-polar Zn1-xCdxO thin films with different Cd content were grown on r-plane sapphire substrates by pulsed laser deposition. The effects of oxygen pressure on Cd content in the Zn1-xCdxO thin films are discussed. Single-phase Zn1-xCdxO thin films with a band gap of about 3.01 eV at room temperature are achieved by incorporating 13 at% Cd content. Based on the X-ray diffraction analysis, the Zn1-xCdxO films with Cd content below 7.2 at% exhibit unique non-polar < 11 (2) over bar0 > orientation, while the films with Cd content above 7.2 at% present < 0 0 0 1 > and < 11 (2) over bar0 > mixed orientations. The surface of Zn1-xCdxO film with pure a-plane orientation shows highly anisotropic morphology with stripes elongated along the c-axis. (C) 2013 Elsevier B.V. All rights reserved.