Effects of Mg salt-modified TiO2 on the photovoltaic performance of dye-sensitized solar cells

This work reports on the preparation of Mg salts [MS; MgCO3 and Mg(CH3COO)2]-modified TiO2 electrodes by very simple dip coating and effects on the photovoltaic properties of dye-sensitized solar cells (DSSCs) with them. The DSSC with MS-modified TiO2 layer showed an increase in short-circuit current (Jsc) and open-circuit voltage (Voc), resulting in a power conversion efficiency (PCE) of 8.48% compared to that (7.27%) of reference device with bare TiO2. The improved Jsc value was attributed to the increased dye adsorption. Electrochemical impedance spectroscopy, dark current–voltage and incident photon-to-current conversion efficiency studies revealed that the Voc enhancement was caused by the conduction band edge shift of TiO2 to a more negative potential due to the formation of a surface dipole.

► Incorporation of Mg salts onto the surface of TiO2 by simple dip coating.
► Conduction-band edge shift of TiO2 due to the formation of surface dipole.
► Enhanced short-circuit current and open-circuit voltage.