Pulsed photothermal modeling of composite samples based on transmission-line theory of heat conduction

A transmission-line approach to obtain the thermal solutions for two- and three-layer samples at the front surface is described. These solutions an fitted to pulsed photothermal reflectance data for a Au/TAC/Si sample. The results indicate that the two- and three-layer models agree with each other and the embedded TAC film can be treated as a thermal resistance. The fitted thermal property of the TAC film is relatively close (K-TAC ranging from 1.77 to 2.21 W/m per K) with different pulse shapes. This indicates that the pulse shape function does not play a significant role in the TAC film's thermal property determination. However, the fitted thermal property of the Au layer is highly pulse shape function dependent (K-AU ranging from 71 to 280 W/m per K). There one finds that the pulse shape function needs to match the excitation pulse in order to obtain the correct thermal property of the Au layer. (C) 1999 Elsevier Science S.A. All rights reserved.