Solid State Physics Laboratory was started with two major research fields namely Crystal growth and Thin film Technology. In the field of crystal growth we have successfully prepared large sized single crystals by employing Czochralski method and Gel method. Czochralski method is used to obtain large sized single crystals with high crystalline perfection at high speeds. Gel method is an alternate technique to solution growth with controlled diffusion. It is used to grow crystals from solutions of substances having very high solubility. In the field of thin film technology we have successfully prepared metal chalcogenide compound semiconducting thin films that are suitable for photovoltaic applications. 13 people have successfully completed their Ph.D. work in these fields. We have about 90 publications in reputed national and international journals and more than 25 presentations in national and international conferences. We also have successfully completed 9 external funded projects.
At present our work is concentrated mainly on the preparation and characterization of compound semiconducting thin films and is headed by Prof. B. Pradeep. Reactive evaporation is used as the deposition technique. The structural, optical and electrical properties of the reactively evaporated films are also studied.
Reactive Evaporation - a variant of Gunther’s three temperature method. It is based on the fact that continuous condensation of a given vapor at a given deposition rate takes place only if substrate temperature drops below a critical value. For binary systems deposition of stoichiometric compound layers by simultaneous evaporation of Individual components are possible only by selecting a suitable substrate temperature and adequate incident rate for the individual components. Some of the main advantages of this method is that the synthesis of compounds from elements prior to deposition is eliminated and also requirement of high temperature for the evaporation and subsequent decomposition of the compound is avoided. Conventional vacuum system operated in the range of 10-5 mbar is used for preparation of the film. We have successfully prepared transparent conducting oxides like SnO2, In2O3, ITO, binary and ternary compound semiconducting thin films of selenides, tellurides and sulphides of certain metals like Cu, Pb, Ag, Sn, In etc. Our recent interest is in the development, characterization and optimization of metal chalcogenide semiconducting thin films like AgSbSe2, PbSb2Se4 and CuInSe2. These materials have very good applications in thermoelectric devices and solar cell fabrication.