Crystallized Nano-thick TiO₂ films with low temperature ALD process

To enhance the efficiency of dye sensitized solar cells, we proposed crystalline anatase-TiO₂ by using a low temperature process (150°C-250°C;). We successfully fabricated 30 nm-TiO₂ at a fixed atomic layer deposition condition of 1.0 sec of TDMAT pulse, 20 sec of TDMAT purge, 0.5 sec of H₂O pulse, and 20 sec of H₂O purge. In order to examine the microstructure, phase, and band-gap of the TiO₂ respectively, we employed a Nano-Spec, transmission electron microscope, high resolution XRD, Auger electron spectroscopy, scanning probe microscope, and UV-VIS-NIR. We were able to fabricate a crystalline anatase-phase of 30 nmTiO₂ successfully at temperatures above 180°C. Our results showed that our proposed low temperature ALD process (below 20°C) might be applicable to glass and flexible polymer substrates.