Design and fabrication of a photothermal spectrometer and investigations of multilayer thin films

In this work we present the results of our attempt to build a compact\nphotothermal spectrometer capable of both manual and automated mode of\noperation.The\nsalient features of the system include the ability to analyse thin film, powder\nand polymer samples. The tool has been in use to investigate thermal, optical\nand transport properties. Binary and ternary semiconducting thin films were\nanalysed for their thermal diffusivities. The system could perform thickness\nmeasurements nondestructively. Ion implanted semiconductors are widely\nstudied for the effect of radiation induced defects. We could perform\nnondestructive imaging of defects using our spectrometer.The results reported in his thesis on the above in\naddition to studies on In2S3 and transparent conducting oxide ZnO have been\nachieved with this spectrometer. Various polymer samples have been easily\nanalysed for their thermal diffusivities. The technique provided ease of\nanalysis not achieved with conventional techniques like TGA and DSC.\nIndustrial application of the tool has also been proved by analyzing defects of\nwelded joints and adhesion of paints. Indigenization of the expensive lock-in-amplifier\nand automation has been the significant achievement in the course of\nthis dissertation. We are on our way to prove the noise rejection capabilities of\nour PC LIA.