Epitaxial growth of Cu2O and ZnO using different approaches

Latvijas Universitātes Cietvielu fizikas institūta, Doktorantūras skolas „Funkcionālie materiāli un nanotehnoloģijas” zinātniskais seminārs 19. novembrī plkst. 10:00, LU CFI, Ķengaraga ielā 8, 2.stāva zālē Professor Dr. phys. Liuwen Chang (Department of Materials and Optoelectronic Science, National Sun Yat-sen University, Kaohsiung, Taiwan, R. O. C.).

The researches of epitaxial growth of oxide semiconductors were conducted traditionally on single-crystal substrates with low-indexed planes by vapor deposition in vacuum at high temperatures. In order to improve the layer-by-layer growth of the epitaxial films, the effects of substrate-off-cut and lattice misfit between substrate and film are issues frequently discussed. However, the low-lattice-misfit substrates having a desired off-cut are sometime not available or very expensive. An alternative strategy for epitaxial growth was suggested recently, especially for exploring new substrates or new orientations, by using polycrystalline substrates. A well-polished polycrystalline substrate can provide grains of various orientations and off-cut angles from a low-indexed plane. Instead, electron backscatter diffraction associated with the secondary electron imaging is suitable techniques to identify the orientation and surface smoothness of the grown films. Electrodeposition provides the merits of low processing temperature and low cost on instruments. In this presentation, examples of growing Cu2O and ZnO epilayers on Cu substrate by molecular beam epitaxy and electrodeposition using the “combinatory substrate approach” will be discussed in detail.