Production of porous nanostructured zinc oxide thin films by pulsed laser deposition

Pulsed laser deposition has been used to produce porous nanostructured zinc oxide (ZnO) thin films. A laser produced ZnO plasma plume was deposited at a highly oblique incident angle onto rotating silicon (Si) substrates resulting in porous thin films consist of isolated ZnO posts or helices with diameters around 100 nm. These posts and helices were formed due to a self-shadowing mechanism, at fast and slow substrate rotation speeds, respectively. These films were deposited on Si substrates at room temperature at the presence of 0.07 Torr oxygen and the films were annealed at 600 °C for 2 h after deposition. Strong UV and negligible visible photoluminescence emissions were observed from these ZnO films.