Structural and physical properties of ZnO on lithium niobates with two domains

In this paper, we investigated epitaxial ZnO thin films grown on LiNbO3 {0001} substrates with positive (+c) and negative (-c) polarization charges terminated surfaces by using pulsed laser deposition. The polarizations of LiNbO3 substrates can play an important role on modulating structural and physical properties of ZnO thin films. X-ray diffraction studies revealed that the growth behavior of ZnO films was significantly dependent on the temperature and oxygen partial pressure. At the optimal deposition condition, ZnO thin films were grown on two substrates, LiNbO3 (0001) and (000-1) substrates, which have +c and-c domain, respectively. ZnO/LiNiO3(-c) exhibited a sharp rocking curve with highly-oriented out-of-plane than that of ZnO/LiNbO3(+c). The polarization of the substrates was attributed to the carrier concentration and resistance of ZnO layers. After thermal cycles, the resistance between two samples became clearly different due to the elimination of adsorbates, indicating the possibility of polarization-induced charge accumulation in ZnO/LiNbO3 systems.