(596b) Facile Fabrication of Lead Chalcogenide Thin Films with Controlled Structure and Composition
Our group has identified a route to overcoming this challenge that utilizes a thiol-amine reaction system. We have shown that combining a lead halide solution and a chalcogen solution in select thiol-amine mixtures leads to the creation of lead chalcogenide nanoparticles and their microscale assemblies6. This synthesis occurs instantaneously at room temperature and allows for control over assembly size through thiol-amine variations, making it both facile and tunable.
Building off of that work, in this report we exploit these assembly properties of PbTe in thiol-amine mixtures to fabricate PbTe thin films from solution at room temperature within the order of minutes. These films exhibit features on the length scale of nanometers to micrometers and display intimate contact amongst nano/micro-particles. This contact shows promise towards overcoming the traditional electrical limitations of solution-processed thermoelectric materials and eliminates the need for further processing often required by other techniques. With the reduced complexity and feature size relevant to improved thermoelectric properties, this method of film formation offers a facile alternative to traditional PbTe synthetic techniques.
To further demonstrate the tunability of this fabrication method, we will also present a novel room-temperature method of introducing selenium into these PbTe materials. This introduction of selenium allows us to create films that closely mirror the composition of materials from literature that display some of the highest reported thermoelectric figures of merit. We will then present the thermoelectric properties of the PbTe thin films resulting from this fabrication method and their dependence on grain size and composition. The capabilities of this fabrication method then offer promise towards a tunable, low intensity route amenable to large scale production of lead chalcogenide thin film materials.
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