Contents lists available at ScienceDirect Optics and Laser Technology journal homepage: www.elsevier.com/locate/optlastec Full length article Synthesis of Au/Si nanocomposite using laser ablation method Pedram Nasiri, Davoud Doranian ⁎ , Amir Hossein Sari Laser Lab., Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran, Iran HIGHLIGHTS • Laser ablation method is a strong tool to produce nanocomposite (Au/Si). • Plasmonic absorption peak of Au nanoparticle makes energy transfer to the system. • Morphology of nanocomposites is under the influence of their volumetric ratio. • Size of nanostructures may be decreased by secondary laser irradiation. • Oxygen bonds may be removed from oxide nanoparticles after laser irradiation. ARTICLE INFO Keywords: Laser ablation Nanocomposite Plasmonic absorption Gold/silicon nanocomposite Self-organization ABSTRACT Production and characterization of gold/silicon nanocomposites have been investigated experimentally, using laser ablation method. Firstly Si nanoparticles and Au nanoparticles were synthesized by ablation of their bulk in deionized water with the fundamental wavelength of Nd:YAG pulsed laser separately. Then the produced Au nanoparticles and Si nanoparticles suspensions were mixed and irradiated with the second harmonic of the pulsed Nd:YAG laser operating at 532 nm. Effects of the volumetric ratio of Au and Si nanoparticle suspensions in the characteristics of Au/Si nanocomposite have been studied in this research. A variety of analytical techniques such as UV–Vis-NIR spectroscopy, X-ray diffraction, DLS measurement, FTIR spectrum, photoluminescence spectroscopy, and TEM and SEM imaging were applied to characterize the products. Strong plasmonic absorp- tion band of Au nanoparticles around 530 nm made them to be heated and melted by the green laser irradiation to form nanocomposite with Si nanoparticles nearby. 1. Introduction First studies on the nature of nanostructures were started since al- most 50 years ago [1]. Experimental and theoretical investigations on this topic have leaded to valuable discoveries of the production of na- nostructures and their potential in various applications of nano- technology [2]. Nowadays, nanocomposites are employed in multiple technological fields such as electronics, optics, medical fields, material modifying and many other fields [3–8]. Nanocomposites have gained much interest recently. Significant efforts are underway to control the nanostructures via innovative synthetic approaches [9–17]. Character- istics of nanocomposites are not only depends on its constituent mate- rials but also to its size, structure and formation and it can exhibit different properties from its individual constituent materials and also its bulk form [18]. Coming to our subject, nanometer size noble metals such as gold and semiconductors such as silicon has vast usages in electronics and optics for their special properties [18–21]. Nanocomposite structures containing both metals and semiconductors are expected to have im- portant practical applications due to the fact that they exhibit surface plasmonic and excitonic resonance simultaneously [22,23]. Thus na- nocomposites of metal and semiconductors such as Au/Si have at- tracted significant interests due to their noticeable potential in the wide range of applications [24,25]. According to Kleps and his co-worker’s report, Au nanoparticles on Si layer are greatly used in increasing substrate biocompatibility properties [26]. Derkacs et al. fabricated and characterized hydro- genated amorphous silicon thin film solar cells in which Au nano- particles have been employed to engineer the transmission and spatial distribution of electromagnetic fields within the hydrogenated amor- phous silicon layer [27]. Lin et al. fabricated a highly sensitive surface- enhanced Raman spectroscop substrate composed by ordered hex- agonal-packed Si nanorod arrays joined with homogeneous Au nano- particles [28]. Also Zhao et al. fabricated Au-Si nano-particle-decorated https://doi.org/10.1016/j.optlastec.2018.12.033 Received 11 August 2018; Received in revised form 4 November 2018; Accepted 22 December 2018 ⁎ Corresponding author. E-mail address: doran@srbiau.ac.ir (D. Doranian). Optics and Laser Technology 113 (2019) 217–224 0030-3992/ © 2018 Elsevier Ltd. All rights reserved. T