Photothermal technique using individual cantilevers for quality monitoring in thin film devices.

An innovative photothermal technique has been developed to obtain optical absorption spectra of thin film devices. This technique is based on the bending effect induced by thermal expansion of a cantilever. The thin and transparent cantilever contacts a sample and when the sample is heated by photoexcitation, heat flows into the cantilever. The thermal expansion on sample side of the cantilever causes bending of cantilever beam. Main advantage of this method is adaptable to measure any sample structure and this can be used for quality monitoring in thin film devices such as solar cells and optical disks.