Laser patterning of Zn for ZnO nanostructure growth: Comparison between laser induced forward transfer in air and in vacuum

This study reports patterning of surfaces with Zn using the laser induced forward transfer (LIFT) technique and subsequent chemical growth of ZnO thin films. The LIFT process is performed both in vacuum and in air and yields a Zn pattern on the receiving substrate. These Zn patterns were used as precursors to chemically grown ZnO thin films, and the morphology of these films was investigated and compared. Inspection of the films grown from the in-vacuum deposited pattern revealed the aligned growth of ZnO nanorods (NRs), in the regions where the Zn precursor was deposited, while no substantial ZnO growth was observed outside the precursor patterns. The ZnO films grown from the in-air deposited patterns show different growth behaviour; the precursor pattern is not well preserved and the surface morphology reveals flower-type ZnO nanorods. The difference in morphology of the seeding Zn patterns deposited under the two environments (vacuum versus air) directly translates into different morphology ZnO features, chemically grown from these patterns (nanorod versus flower growth).