Investigations the structural, optical and photovoltaic properties of La doped TiO2 photoanode based dye sensitized solar cells
M.I. Khan, Bilal Mehmood, Muhammad Abubakr Naeem, Mehran Younis, Khaled H. Mahmoud, Zeinhom M. El‐Bahy, Waqas Siddique Subhani, Saddam Hussain, Norah Alwadai, Hind Albalawi, Munawar Iqbal
Abstract
Films of TiO 2 , La-doped TiO 2 (La–TiO 2 ), La–TiO 2 /TiO 2 and TiO 2 /La–TiO 2 are prepared by sol-gel (dip coating) route. The structural properties like phase, grain size , dislocation line density, inter-planner distance, and lattice parameters are calculated by X-ray diffractometer (XRD). All films have anatase phase which is good for solar cells application. Film of La-doped TiO 2 /TiO 2 has high grain size. The optical properties like transmittance , absorbance, refractive index , extinction coefficient , dielectric constants and band gap are measured by UV–Vis spectroscopy. The film of La-doped TiO 2 /TiO 2 has low bandgap and high transmittance in visible range making it a good candidate for dye sensitized solar cells (DSSCs). DSSCs from these electrodes are prepared by using electrolyte (iodide/tri-iodide) and dye (N719). 1% La–TiO 2 /TiO 2 based cell has highest open-circuit voltage (0.74 V), Fill-Factor (0.73), short-circuit current density (6.57 mA/cm 2 ), and efficiency (3.53%) as compared to other cells. Low value of bandgap energy, weak recombination rate, improvement in charge transfer rate is mainly responsible to achieve highest efficiency rate (3.53%).