Femtosecond laser deposition of TiO2 nanoparticle-assembled films with embedded CdS nanoparticles

Abstract

Based on the normal pulsed laser ablation method, femtosecond pulsed laser deposition (fs-PLD) is adopted in vacuum for the production of TiO2 nanoparticle-assembled films. We study the morphology and electronic characteristics of TiO2 nanoparticle-assembled films deposited at different oxygen background gas pressures from high vacuum (∼10−4 Pa) to 100 Pa and different deposition time. Our results show that TiO2 nanoparticle-assembled films obtained in high vacuum present both a mixture with rutile phase and anatase phase and a pure rutile phase. At the same time, there are more mesoporous structures in the film after annealing, which is beneficial for the enhancement of photocatalytic activity. In water splitting experiment, part of the TiO2 nanoparticle-assembled films embedded with a small mass fraction of CdS nanoparticles (∼5%) present an interesting photocurrent enhancement with a maximum value of ∼0.2 mA/cm2 under a solar simulator.