Search for: All records

Abstract The development of new materials and their compositional and microstructural optimization are essential in regard to next-generation technologies such as clean energy and environmental sustainability. However, materials discovery and optimization have been a frustratingly slow process. The Edisonian trial-and-error process is time consuming and resource inefficient, particularly when contrasted with vast materials design spaces¹. Whereas traditional combinatorial deposition methods can generate material libraries^2,3, these suffer from limited material options and inability to leverage major breakthroughs in nanomaterial synthesis. Here we report a high-throughput combinatorial printing method capable of fabricating materials with compositional gradients at microscale spatial resolution. In situ mixing and printing in the aerosol phase allows instantaneous tuning of the mixing ratio of a broad range of materials on the fly, which is an important feature unobtainable in conventional multimaterials printing using feedstocks in liquid–liquid or solid–solid phases^4–6. We demonstrate a variety of high-throughput printing strategies and applications in combinatorial doping, functional grading and chemical reaction, enabling materials exploration of doped chalcogenides and compositionally graded materials with gradient properties. The ability to combine the top-down design freedom of additive manufacturing with bottom-up control over local material compositions promises the development of compositionally complex materials inaccessible via conventional manufacturing approaches. 

Quaternary chalcogenides continue to be of interest due to the variety of physical properties they possess, as well as their potential for different applications of interest. Investigations on materials with the sphalerite crystal structure have only recently begun. In this study we have synthesized sulfur-based sphalerite quaternary chalcogenides, including off-stoichiometric compositions, and investigated the temperature-dependent electronic, thermal and structural properties of these materials. Insulating to semiconducting transport is observed with stoichiometric variation, and analyses of heat capacity and thermal expansion revealed lattice anharmonicity that contributes to the low thermal conductivity these materials possess. We include similar analyses for CuZn 2 InSe 4 and compare these sphalerite quaternary chalcogenides to that of zinc blende binaries in order to fully understand the origin of the low thermal conductivity these quaternary chalcogenides possess.