Growth of a-plane ZnO thin films on LaAlO3(100) substrate by metal-organic chemical vapor deposition

Control of a- and c-plane preferential orientations of ZnO thin films

“…The c-plane ZnO films are known to usually exhibit grains with a circular shape and the a-plane ZnO films show various types of grain structures, such as weave, circle, stripe, ellipse, etc. [5,7,20,21]. In this work, a-plane ZnO grains were in circular shape, which is rather similar to that of c-plane ZnO grains.…”

“…The film/substrate interfacial energy of ZnO(1 12 0)/ LAO system is much lower than that of ZnO(0 0 0 2)/LAO, because the lattice matching causes a large decreasing in the interfacial energy [18]. Tian et al [5] reported that ZnO film grown on LAO substrate exhibited a-plane with weak c-plane reflection at high temperature (T s = 600 8C). However, our result indicates that the aplane orientation becomes more marked with increasing T s , whereas the c-plane orientation becomes more imperceptible, because the deposited atoms can migrate for a relatively long time on the substrate to arrive at suitable lattice site as increasing T s [19].…”

“…Over the past years, thin films of ZnO have been fabricated by various methods such as sputtering, pulsed laser deposition, atomic layer deposition, molecular-beam epitaxy, and metal organic chemical vapor deposition. ZnO is known to readily exhibit c-axis preferred orientation on single-crystalline substrates and even on amorphous substrates such as glass, and amorphous Al 2 O 3 , has been reported [5][6][7][8]. However, the controlled orientation behavior and the orientation-dependent properties of ZnO films have not been reported in detail yet.…”

Structural characterization of impurified zinc oxide thin films

“…There are studies that report the same dominant behavior of (110) preferred orientation of the ZnO-based thin films deposited on such substrates [41,42,43], but also some that presented (002) dominant orientation [44,45]. The preferential growth mode is influenced by both substrate cleaning process and deposition parameters.…”

Surface morphology, structural and optical properties of polar and non-polar ZnO thin films: A comparative study

“…Because ZnO has no inversion symmetry, ZnO crystal along the c-axis has alternate zinc ion layers with oxygen ion layers, which cause polarization along the c-axis. Generally, the electric field induced by polarization has negative effects on optical and electrical properties of devices [5]. For instance, a decrease in the overlapping of the electron and hole wave function in the quantum well will result in a decrease of internal quantum efficiency of the LEDs and LDs [6][7][8].…”