Preparation of large-area dye-sensitized solar cells based on hydrothermally synthesized nitrogen-doped TiO2 powders

Low-cost, yellowish, nanocrystalline nitrogen-doped titanium dioxide (N-doped TiO2) powder was synthesized by a hydrothermal method. The as-prepared N-doped TiO2 powder was characterized by X-ray diffraction, transmission electron microscopy (TEM), UV–Vis absorption spectra, X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller analysis techniques. The grain size of the prepared powder was around 13 nm as estimated by both Scherrer’s method and TEM images. The effect of the ratio of N-doped TiO2 particles to Degussa P25 on the photovoltaic performance of large-area dye-sensitized solar cells (DSSCs) was also investigated. The N-doped TiO2 electrode showed higher photovoltaic performance compared with that of pure P25 at constant irradiation of 100 mW cm−2, which is attributed to the large pore size and high surface area of N-doped TiO2 resulting in the introduction of extra charge carrier pathways that could be beneficial for overall charge transportation. Energy conversion efficiency of 5.12 % was achieved in a DSSC device with active area of 51.19 cm2.