Department of Mechanical & Materials Engineering, Florida International University
Nanoscale precursors have been found useful in thin film generating for a variety of applications, from optoelectronics to medical devices. When endowed with adequate functionality, nanostructured chalcogenides are readily dispersible in various solvents to create colloidal solutions. Such dispersions, often called inks, could be easily coated in large areas on conducting substrates, conferring an inexpensive and robust method to construct thin films that could be useful in a plethora of applications, including energy generation; specifically, in thin-film photovoltaics. The processing required for obtaining uniform and dense nanostructured coatings is governed by the ability to tailor particle size, particle size distribution, nanoprecursors' surface and to select appropriate dispersion reagents. Each type of nanostructure is unique, and finding a specific set of conditions requires an in-depth analysis of properties such as surface identity and morphology. With melting occurring at several hundred degrees lower than the melting point in bulk, the thermal treatment of NP precursors enables fabrication of uniform, crystalline thin-films on inexpensive substrates which only sustain moderate processing temperatures. The operating hypothesis is that the final crystalline film will mirror the nanoprecursors composition prior to the thermal treatment. Therefore, tremendous efforts have been reported toward rigorous control of nanoparticles composition.
The presentation will outline our discoveries in the synthesis of nanostructured materials for thin-film chalcogenide photovoltaics (PV), including Cu2ZnSnS4, Fe2GeS4, and Cu3VS4, and will dive into preparative methods for a new class of materials, 2D chalcogenides, the focus of our most recent endeavors.