Opto-electrical properties and chemisorption reactivity of Ga-doped ZnO nanopagodas

ZnO nanostructures with Ga doping prepared by metal-organic chemical vapor deposition developed an interesting nanopagoda shape with exposed {11 21}, {11 $($) over bar $ 22}, {$($) over bar $ 2201}, and { 1101} lateral planes instead of {10 $($) over bar $ 10} and {11 $($) over bar $ 20} in the usually observed ZnO nanorods or nanowires. The types of exposed planes strongly affect those properties relating to surface reactivity. In this work, we report the opto-electrical properties and chemical reactivity of the Ga-doped ZnO nanopagodas and ZnO nanowires. Ultraviolet responses of photodetectors demonstrated that Ga-doped ZnO nanopagodas not only possessed a faster electron-hole generation and recombination rate but also exhibited higher photocatalytic activities than the ZnO nanowires. The improved performance of Ga-doped ZnO nanopagodas is due to the enhanced O-2 and H2O chemisorption reactivity of the {11 $($) over bar $ 21}, {11 $($) over bar $ 22}, {$($) over bar $ 2201}, and {$($) over bar $ 1101} planes relative to the {10 $($) over bar $ 10} and {11 $($) over bar $ 20} planes.