Abstract |
We examined the microstructure and optical properties of crystallized ~30 nm-ZnO/~10 nm amorphous TiO2 nano bilayered films as nano electrodes were deposited at extremely low substrate temperatures of 150-210℃. The bilayered films were deposited on silicon substrates with 10 cm diameters by ALD (atomic layer deposition) using DEZn (diethyl zinc(Zn(C2H5)2)) and TDMAT (tetrakis dimethyl-amid titanium(Ti(N(CH3)2)4) as the ZnO and TiO2 precursors, respectively, and H2O as the oxidant. The microstructure, phase, and optical properties of the bilayered films were examined by FE-SEM, TEM, XRD, AES, and UV-VIS-NIR spectroscopy. FE-SEM and TEM showed that all bilayered films were deposited very uniformly and showed crystallized ZnO and amorphous TiO2 layers. AES depth profiling showed that the ZnO and TiO2 films had a stoichiometric composition of 1:1 and 1:2, respectively. These bilayered films have optical absorption properties in a wide range of ultraviolet wavelengths, 250-390 nm, whereas the single ZnO and TiO2 films showed an absorption range of 350-380nm. |
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Key Words |
thin films, ALD, optical properties, AES, bilayered |
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