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Pure and doped niobium oxide (Nb 2 O 5) layers are electrochromic (EC) materials which change their color by insertion of Li + ions from transparent to brown, grey or blue depending on the crystallinity of the layer. EC devices with the configuration K glass/EC layer/composite electrolyte/ion storage (IS) layer/K glass, were produced using different Nb 2 O 5 EC layers, a (CeO 2) x (TiO 2) 1Àx (x 0.45) IS layer and an inorganic organic composite electrolyte to which a small amount of water (up to 3 wt.%) was added. The grey coloring all solid state sol gel devices fabricated with Nb 2 O 5 : Mo coatings show a high reversible coloration (DOD 0.3) and a long term stability of more than 55 000 switching cycles. Large area EC devices (30 Â 40 cm) show a transmittance change between 60% and 25% at 550 nm after galvanostatic coloration and bleaching for 3 min and a coloration efficiency of 27 cm 2 /C. The results obtained with blue and brown coloring Nb 2 O 5 EC layers and a comparison with blue coloring WO 3 layers are also presented.

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Tin doped indium oxide (ITO) thin films provide excellent transparency and conductivity for electrodes in displays and photovoltaic systems. Current advances in producing printable ITO inks are reducing the volume of wasted indium during thin film patterning. However, their applicability to flexible electronics is hindered by the need for high temperature processing that results in damage to conventional polymer substrates. Here, we detail the conditions under which laser heating can be used as a replacement for oven and furnace treatments. Measurements of the optical properties of both the printed ITO film and the polymer substrate (polyethylene terephthalate, PET) identify that in the 1.5–2.0 μm wavelength band there is absorption in the ITO film but good transparency in PET. Hence, laser light that is not absorbed in the film does not go on to add a deleterious energy loading to the substrate. Localization of the energy deposition in the film is further enhanced by using ultrashort laser pulses (~1 ps) thus limiting heat flow during the interaction. Under these conditions, laser processing of the printed ITO films results in an improvement of the conductivity without damage to the PET.