Abstract
We report the formation of TiO
2 nanotube layers by anodization process and effect of Cr
+ implantation doses on structure and photoresponse of the annealed (anatase) TiO
2 nanotubes. A subsequent thermal annealing leads to a healing of the structure and so leading to an increased photocurrent magnitude in the visible range.
Layers of TiO
2 nanotubes have been fabricated by electrochemical anodization of Ti. After annealing the tubes to an anatase structure Cr doping was carried out by ion implantation at an energy of 60
keV and at two nominal fluences, 5
×
10
15
cm
−2 and 5
×
10
16
cm
−2.
XRD measurements reveal that the anatase structure shows a certain degree of ‘amorphization’ after ion implantation. However, this effect can be reversed by subsequent thermal annealing.
Photoelectrochemical measurements show a visible photoresponse for the Cr
+ implanted tubes. Reannealing the tubes, leads to an increase in the photoresponce magnitude in the visible range of the solar spectrum.