Homoepitaxial growth of non-polar ZnO (11(2)over-bar-0) films on off-angle ZnO substrates by MOCVD

Homoepitaxial ZnO (11 (2) over bar0) films were successfully prepared on single crystal ZnO (11 (2) over bar0) substrates with off-angles of 0 degrees, 1 degrees, 2 degrees and 3 degrees toward the [1 (1) over bar 00] direction by using an atmospheric pressure MOCVD. A striped pattern along the ZnO [0 0 0 1] direction was observed in ZnO films, and surface smoothness of ZnO films was remarkably improved by increase in off-angle. Full-width at half-maximum of XRD patterns of rocking curves and 2 theta-omega scans for (0 0 0 2) and (10 (1) over bar0) planes measured by grazing incident diffraction measurement was decreased with increase in off-angles. Free exciton emissions and donor-bound exciton emissions were clearly observed in the photoluminescence (PL) spectra of ZnO films deposited on ZnO substrates with off-angles measured at 5 K. Room temperature PL spectra of ZnO films have a strong band edge emission on the samples with ZnO films deposited on off-angle substrates. (c) 2006 Elsevier B.V. All rights reserved.