“…Compared to similar ZnO-based devices with power efficiency of up to 1.6%, ZnO nanotube-based cells showed exceptional photovoltage, but the higher surface area may absorb excess dye molecules (Martinson et al, 2007). Besides ZnO, some other binary metal oxides, such as Fe 2 O 3 , ZrO 2 , Nb 2 O 5 , Al 2 O 3 , and CeO 2, and ternary compounds, such as SrTiO 3 and Zn 2 SnO 4 , have been also studied and tested as photoelectrodes in DSSC, but their efficiency is significantly lower with respect to that of TiO 2 (Moharam et al, 2021).…”