Table 2 Photovoltaic parameters for ZnO@TiO₂ NT-based DSCs as a function of the TiO₂ (meso or anatase) wall thicknesses. - Mean photovoltaic parameters values and estimated errors have been obtained from data of three devices with the same configuration. A ZnO NT cell without TiO₂ has been included for comparison.

250 nm ZnO NT³

1.5 ± 0.2

460 ± 20

50 ± 1

0.3 ± 0.1

ZnO 250 nm@meso-TiO₂ 5 nm NT

0.8 ± 0.1

540 ± 5

44 ± 1

0.2 ± 0.1

ZnO 250 nm@meso-TiO₂ 20 nm NT

0.8 ± 0.1

542 ± 5

47 ± 1

0.2 ± 0.1

ZnO 250 nm@meso-TiO₂ 50 nm NT

0.8 ± 0.1

529 ± 7

49 ± 1

0.2 ± 0.1

ZnO 250 nm/meso-TiO₂ 50 nm TF

0.4 ± 0.1

573 ± 13

40 ± 8

0.1 ± 0.1

ZnO 250 nm@anatase 5 nm NT

0.9 ± 0.1

579 ± 13

38 ± 1

0.2 ± 0.1

ZnO 250 nm@anatase 20 nm NT

1.0 ± 0.1

588 ± 8

43 ± 5

0.2 ± 0.1

ZnO 250 nm@anatase 50 nm NT

1.0 ± 0.2

635 ± 15

32 ± 1

0.2 ± 0.1

ZnO 250 nm/anatase 50 nm TF

0.6 ± 0.2

615 ± 1

38 ± 2

0.1 ± 0.1