Composite zinc/silicon nanocrystalline thin film: preparation, structures and the effect of oxidation on their photoluminescence

Zinc/silicon nanocrystalline thin films were prepared by the pulsed laser d eposition method in a vacuum chamber using a rotary target which exposed th e zinc and silicon materials to the laser alternately. TEM, EDS, AFM, SIMS and XPS results show that the as-prepared sample was a mixture of silicon a nd zinc nanoparticles, which were only slightly oxidized. The existence of silicon nanocrystals was also confirmed by photoluminescence analysis. XPS results confirmed that, when the samples were annealed in the open bur clea n atmosphere, the extent of oxidation of the film increased with temperatur e. When the temperature was increased from room temperature to 500 degreesC , the intensity of the photoluminescence peak from the nanosilicon crystals first increased, then decreased and finally disappeared. A new PL peak fou nd in the wavelength region of 400-550 nm was attributed to ZnO nanoparticl es formed by their interaction with silicon oxide. Our results confirmed th at the interface effect between the Si and Zn nanoparticles strongly affect s the PL of the interfacial ZnO nanoparticles.