Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2014)
    Energy Harvesting & Storage Wednesday Sessions
       Session EH-WeE

Invited Paper EH-WeE4
Laser Processing and Photoacoustic Characterization of Nanomaterials and Thin Films

Wednesday, December 10, 2014, 6:40 pm, Room Lehua

Session: Characterization of Materials for Energy Applications II
Presenter: Mayo Villagrán-Muniz, Universidad Nacional Autonoma de Mexico
Authors: MVM. Villagrán-Muniz, Universidad Nacional Autonoma de Mexico
CSA. Sanchéz-Aké, Universidad Nacional Autonoma de Mexico
F.T. Tenopala, Universidad Nacional Autonoma de Mexico
M.A.V.A. Valverde-Alva, Universidad Nacional Autonoma de Mexico
A.C. Canales, Universidad Nacional Autonoma de Mexico
J.M.DL. Martínez-De León, Universidad Nacional Autonoma de Mexico
B. de la Mora, Universidad Nacional Autonoma de Mexico
C.G.S. García-Segundo, Universidad Nacional Autonoma de Mexico
T.G.F. García-Fernández, Universidad Autónoma de la Ciudad de México, Mexico
F.A.C.M. Alvarez-DelCastillo-Manzanos, Universidad Nacional Autonoma de Mexico
Correspondent: Click to Email
The synthesis of metallic nanoparticles (NPs) either covered or embedded in transparent dielectric thin films has recently received great attention for its possible applications as plasmonic structures. There are several methods to synthesize and incorporate metal NPs such as chemical synthesis, photoreduction, thermal and laser annealing[1]. The annealing methods have the advantage of being free of chemical wastes. The formation of NPs by thermal annealing of thin films inside ovens is the result of the minimization of surface energy, and thus the disaggregation of the film into particles. For the case of laser annealing, nanoparticles of few tens of nm are produced irradiating metal thin films with nanosecond laser pulses[2]. The physical mechanisms behind the annealing of metallic thin films have been widely studied[3]. These studies mainly focuses on the resulting final nanostructure as a function of the involved experimental parameters, without studying the evolution of the process in time; notwithstanding the formation of NPs is a time- dependent process. For example, the shape and size of the NPs depends on the number of pulses in the case of laser annealing[4]. For the case of thermal annealing, the NPs size strongly depends on the interval of time in which the sample is inside the oven[5]. In this work we study the formation of gold NPs by thermal and laser annealing of thin films. Simultaneously we use pulsed- photoacoustic and laser scattering techniques to analyze in situ the synthesis of NPs during the annealing process. The influence of the initial film thickness on the size and size distribution of the resulting NPs was studied. The cumulative effect of the laser pulses and the temperature and annealing time were also analyzed. The changes in the photoacoustic signal and in the scattered intensity of the laser were compared with the SEM images of the samples. The current results suggest that both techniques are suitable for real time monitoring of the changes produced by the annealing. [1] M.J. Beliatis, S.J. Henley, S. Han, K. Gandhi, A.A.D.T. Adikaari, E. Stratakis, E. Kymakis, S.R.P. Silva, Phys. Chem. Chem. Phys., 15, 8237, 2013. [2] S. Imamovaa, N. Nedyalkov, A. Dikovska, P. Atanasov, M. Sawczak, R. Jendrzejewski, G. Sliwinski, M. Obara, Appl. Surf. Sci., 257, 1075-1079, 2010. [3] C.V. Thompson, Annu. Rev. Mater. Res., 42, 399-434, 2012. [4] H. Krishna, N. Shirato, C. Favazza, R. Kalyanaraman, J. Mater. Res., 26(2), 154-169, 2011. [5] C. Worsch, M. Kracker, W. Wisniewski, C. Russel, Thin solid films 520, 4941-4946, 2012.