HETEROEPITAXY OF ZNO ON GAN AND ITS IMPLICATIONS FOR FABRICATION OF HYBRID OPTOELECTRONIC DEVICES

ZnO thin films have been grown heteroepitaxially on epi-GaN/sapphire ( 0001) substrates. Rutherford backscattering spectroscopy, ion channeli ng, and high resolution transmission electron microscopy studies revea led high-quality epitaxial growth of ZnO on GaN with an atomically sha rp interface. The x-ray diffraction and ion channeling measurements in dicate near perfect alignment of the ZnO epilayers on GaN as compared to those grown directly on sapphire (0001). Low-temperature cathodolum inescence studies also indicate high optical quality of these films pr esumably due to the close lattice match and stacking order between ZnO and GaN. Lattice-matched epitaxy and good luminescence properties of ZnO/GaN heterostructures are thus promising for ultraviolet lasers. Th ese heterostructures demonstrate the feasibility of integrating hybrid ZnO/GaN optoelectronic devices. (C) 1998 American Institute of Physic s.