THERMAL-DIFFUSIVITY MEASUREMENT OF MICRON-THICK SEMICONDUCTOR-FILMS BY MIRAGE DETECTION

We describe a method using the mirage detection technique for thermal diffusivity measurements of thin films. High frequency measurements are required for such materials. By determining the difference between two phase measurements, we have been able to avoid probe beam size effects which strongly affect the high frequency responses. The thermal diffusivity of a polycrystalline semiconductor thin film has been measured by using optical heating and compared with the corresponding single-crystal diffusivity. The thermal diffusivity of polymer semiconductor thin films has been obtained for various dopings by using electrical heating.