Effect of MeV Si Ion Bombardment on Thermoelectric Properties of
Sequentially Deposited SiO2/AuxSiO2(1-x) Nanolayers

We prepared 50 periodic nano-layers of electro-cooling system consisting of SiO2/AuxSiO2(1_x) super lattice with Au layer deposited on both sides as metal contacts. The deposited multilayer films have a periodic
structure consisting of alternating layers where each layer is 10 nm thick. The purpose of this research is to tailor the figure of merit of layered structures used as thermoelectric generators. The super lattices
were then bombarded by 5 MeV Si ions at three different fluences to form nano-cluster structure. Rutherford backscattering spectrometry (RBS) was used to monitor the film thickness and stoichiometry before and after MeV bombardment. We measured the thermoelectric efficiency of the fabricated device before and after 5 MeV bombardments measuring the cross plane thermal conductivity by third harmonic method, measuring cross plane Seebeck coefficient, and measuring electrical conductivity using Van der Pauw method. As predicted the electronic energy deposited due to ionization by MeV Si beam in its track produces nano-scale structures which disrupt and confine phonon transmission therefore reducing thermal conductivity, increasing electron density of state so as to increase Seebeck coefficient, and electric conductivity, thus increasing figure of merit.

Bio: Dr.Satilmis Budak got his Ph.D. on the Ferromagnetic Resonance studies of some metal oxides thin films like perovskite with CMR and GMR in Turkey. Then, he started to work in the University of Alabama with
Dr.Arunava Gupta as a postdoc on 14 January 2004 on building of pulsed laser deposition and chemical vapor deposition systems for magnetic thin films and semiconductor nanowires. He has joined the Center for
Irradiation of Materials group in Alabama A&M University to work with Dr.Daryush ILA as a postdoc-research associate on 1 July 2005. Then, he has joined the Department of Electrical Engineering as a faculty in 2007.
He is currently working on growth and applications of the nanowires, fabrication of multilayer nano layer films for building of high efficient thermoelectric generator.

S. Boudak

Alabama A&M University