One-step method to simultaneously grow TiO2 compact and porous layers for DSSC photoelectrodes

Abstract

The growing demand for alternative energy sources has driven significant developments in novel device designs that generate energy through light conversion. Among the different types of solar cells, dye-sensitized solar cells (DSSCs) have emerged as one of the most promising options due to their potential to approach theoretical efficiencies of up to 46%. Although current real-world efficiencies typically range from 10 to 14% that generates numerous opportunity areas for DSSC improvement through different strategies, including the development of innovative solar cell structures, new growth or synthesis processes, and the integration of novel oxide materials. Titanium dioxide is one of the most significant oxide semiconductors and its interest has notably increased in recent years due to its unique optoelectronic properties and its applications in dye-sensitized solar cells (DSSCs). In DSSCs, photoelectrodes play a vital role in photoconversion. Photoelectrodes for DSSCs require blocking and porous oxide semiconductor layers to prevent electron leakage and enhance efficiency. Typically, these layers are produced through various techniques and steps, complicating the fabrication process and extending processing times. Therefore, in this work, we propose a one-step method to simultaneously grow TiO₂-blocking and porous layers for DSSC photoelectrodes at relatively low temperatures. Characterization results using FESEM/EDS, XRD, and UV–visible spectroscopy confirm the growth of both compact and porous layers. These layers are composed of the anatase particulate deposits (100–200 nm) with acceptable grain sizes (17.3–84.1 nm) and exhibit a suitable band gap (3.14 eV). Finally, TiO₂ films were applied in DSSCs as photoelectrodes and showed promising performance in solar cell prototypes.