Fabrication of ultra-flat c-axis oriented ZnO thin films on atomically stepped cyclo-olefin polymer (COP) substrates by pulsed laser deposition at RT

Abstract

Abstract Highly crystalline c-axis oriented ZnO thin films with ultra-flat surfaces were fabricated by pulsed laser deposition at RT on 0.3 nm high atomically stepped cyclo-olefin polymer (COP) substrates whose surfaces were thermally nanoimprinted using atomically stepped sapphire molds. X-ray diffraction and atomic force microscopy measurements showed that the atomically-controlled surfaces of COP substrates enhanced the c-axis orientation and surface flatness of the crystalline ZnO thin films. The ZnO thin films grown on the atomically stepped COP substrates exhibited atomically stepped surface morphology, and also the optical bandgap of about 3.3 eV and RT resistivity of 5.0 × 10−2 Ω cm.