How Can the Introduction of Zr Ions into TiO Nanomaterial Impact the DSSC Photoconversion Efficiency? A Comprehensive Theoretical and Experimental Consideration.

A series of pure and doped TiO nanomaterials with different Zr ions content have been synthesized by the simple sol-gel method. Both types of materials (nanopowders and nanofilms scratched off of the working electrode's surface) have been characterized in detail by XRD, TEM, and Raman techniques. Inserting dopant ions into the TiO structure has resulted in inhibition of crystal growth and prevention of phase transformation. The role of Zr ions in this process was explained by performing computer simulations. The three structures such as pure anatase, Zr-doped TiO, and tetragonal ZrO have been investigated using density functional theory extended by Hubbard correction. The computational calculations correlate well with experimental results. Formation of defects and broadening of energy bandgap in defected Zr-doped materials have been confirmed. It turned out that the oxygen vacancies with substituting Zr ions in TiO structure have a positive influence on the performance of dye-sensitized solar cells. The overall photoconversion efficiency enhancement up to 8.63% by introducing 3.7% Zr ions into the TiO has been confirmed by I-V curves, EIS, and IPCE measurements. Such efficiency of DSSC utilizing the working electrode made by Zr ions substituted into TiO material lattice has been for the first time reported.