Excimer laser sputtering deposition of skutterudites for thermoelectric applications.

Materials having the skutterudites structure such as CoSb3, IrSb3 and RuPdSb6 have been investigated for their magnetic and thermoelectric properties in the bulk form. Nevertheless, in this form they are difficult to synthesize, and their fabrication requires a long process, involving successive cycles of high pressure melting and grinding. Moreover, this process produces only polycrystalline materials with a small grain size that prevent their practical use for thermoelectric devices. Excimer laser sputtering enables us to sputter and vaporize of a large variety of materials, and as for skutterudites, allowed us the choice of sputtering a target with the complex final composition of the film or the choice of sputtering targets of each elements of the final composition of the film in sequence. By tuning other deposition parameters such as substrate temperature and background pressure it is also possible to adjust the final quality of the deposited thin films. We introduce our experiments using a Lambda-Physics LP240i ArF excimer laser (160 mJ/pulse, 5 Hz). The composition of deposits is studied as a function of deposition parameters. The crystalline structure of deposits is investigated by XRD and compared to previous reports for bulk materials. Thermoelectric properties are also to be discussed.