ZnO-Modified MoO3 Nano-Rods, -Wires, -Belts and -Tubes: Photophysical and Nonlinear Optical Properties

We report a versatile approach to obtain MoO3 nanostructures such as nanorods, nanowires, nanobelts, and nanotubes in thin film form on glass substrates, by incorporating ZnO, via RF magnetron sputtering and controlled subsequent oxidation. The nanostructures growth mechanism has been elucidated on the basis of strain field associated with defect-oriented partial screw dislocation induced by ZnO for the drastic variation of the morphology with respect to ZnO incorporating levels from initial tiny nanorods (pure MoO3) to larger nanorods (at 1%), then to aligned and tilted nanowire arrays (at 3 and 5% respectively), afterward to nanobelts (at 7%), and finally to nanotubes (at 10%). Novel properties of ZnO-incorporated MoO3 nanostructures like enhanced photoluminescence and optical limiting have been brought out. This study opens the door to the potentiality of ZnO-added MoO3 nanostructures to be used as luminescent transparent conducting materials, saturable absorbers, and optical limiters.