Influence of Fluorine doping on electron transport characteristics of TiO2 for Perovskite solar cells: A combined Experimental and DFT analysis

Abstract

In the present work, pure TiO2 and Fluorine doped TiO2 (F–TiO2) thin films were prepared and their effect on the photovoltaic response of perovskite solar cells was investigated. Six samples of Fluorine doping of 0, 2, 4, 6, 8, and 10 at. % were prepared using the spin coating method. The F–TiO2 thin films were analyzed using various characterization techniques, including XRD, SEM, and LCR impedance measurements, to ascertain their structural properties, surface morphology, A.C. conductivity, and dielectric constant. The perovskite solar cells were prepared using F–TiO2 as an electron transport layer, MAPbI3 perovskite as the light absorber layer and NiO as the hole transport layer. Further, the DFT calculations were performed using F–TiO2 and perovskite molecules to investigate the electronic properties of the system. The XRD results indicated the formation of the anatase phase of the TiO2. Images obtained by SEM show the multilayer deposition in perovskite solar cells. Both the experimental and computational analysis suggest that the photovoltaic response of the F– TiO2 perovskite solar cell samples was much more impressive than that of the un-adulterated samples.

Keywords

• Sol-gel
• TiO2
• AC conductivity
• Dielectric constant
• Power conversion efficiency