Conductive and photovoltaic properties of multilayered ultrathin films designed by layer-by-layer assembly of titanium oxides

Titania-based ultrathin films were fabricated by layer-by-layer (LbL) assembly of titanium (IV) bis(ammonium lactato) dihydroxide (TALH) and polyelectrolytes. The thickness of the titania monolayer in the LbL films was 4–5 nm, which was consistent with the particle size of TALH in water. The conductivity and the electron mobility of the LbL films reached 10− 8 S cm− 1 and 10− 5 cm2 V− 1 s− 1, respectively. These results suggest that there exist percolation paths for the electron transport in the LbL film. Furthermore, it is demonstrated that photovoltaic properties of the LbL film can serve as an effective electron-transporting and accepting layer.