Ion Beam Assisted Deposition Enhanced Thermoelectric Properties (with Figure of Merit Above 3.0)

Abstract

Ion Beam Assisted Deposition (IBAD) was used to process a thermoelectric materials system, with high volume fraction and high thermoelectric figure of merit, based on the interaction of composites of two metal nanocrystals in silica substrate prepared by a multilayer structure having alternate layers of metal/material mixture. The alternate layers component of this work either has gold or silver content. The deposited layered structure was bombarded during deposition by 500eV to 10keV argon ions in order to produce nanoclusters in each layer. Using the IBAD method we obtained a much larger volume fraction, compared to our previous work, and a resulting thermal conductivity as low as 1.2 (W/m.k), electrical conductivity nearly as high as 90,000 (1/Ohm.m), square of Seebeck Coefficient as high as 1.37 x 10-7 (V/k)2 at 350K, which translates to a Figure of Merit as high as 3.6.