Deposition of CdS thin films onto Si(111) substrate by PLD with femtosecond pulse

The effect of laser fluence (laser incident energy in the range of 0.5-1.5 mJ/pulse with the same laser spot size of 0.5 mm × 0.7 mm) on the structural quality and optical properties synthesized by femtosecond pulsed-laser deposition has been studied. The structural quality and optical properties of the deposited CdS thin films were investigated by X-ray diffraction, atomic force microscopy and photoluminescence measurement. The studies revealed an improvement in the structural quality and optical properties of the CdS thin films with increasing the laser fluence in some range. However, too high laser fluence could lead to the structural quality and optical properties of the CdS thin films to degrade. We defined the optimum laser incident energy was around 1.2 mJ/pulse. And the kinetic energy of the plasma produced by femtosecond laser strongly affects the structure and properties of the deposited CdS thin films.