Saint Louis University,
Keywords: direct write patterning, 1D-2D hybrid nanomaterials and device architectures, CVD synthesis, in-situ characterisation
Summary:Low dimensional materials assembled in vertical or lateral arrangements, often lead to unique and enhanced properties, and new functionalities. While the preparation of layered architectures usually involves multi-step, fabrication processes it also relies on mask assisted lithographic processes. In this talk I will present our methodology for designing and fabricating 1D and 2D nanostructures such as ZnO nanowires, and layered van der Waals semiconductors MoS2 and WS2 and their heterostructures in a variety of geometric assemblies in a controlled and selective fashion by employing parallel direct-write patterning (DWP) method developed in our Lab. We employ custom aqueous ink precursors and chemical vapor deposition to synthesize high quality nanomaterials on variety of substrates, surfaces, and on suspended platforms, at predefined locations. Our unconventional fabrication approach enables simple and flexible production of not only single materials but also variety of heterostructures 1D-1D, 1D-2D or 2D-2D based on “mix and match” principle directly on top of each other. Location specific synthesis and controlled morphology of the resulting nanomaterials continues to be challenging while at the same time is critically important for technological application where implementation of micro- and nano-scale systems into devices such as sensor, diodes, actuators, sensors can provide exciting new opportunities for exploiting new properties of 1D and 2D nanomaterials in flexible electronics, photovoltaics as well as for biological and biomedical applications. Finally, our bottom-up approach allows us to engineer pristine as-grown interfaces and rapid testing of materials’ quality, crystallinity, and chemical composition as well as their compatibility for specific targeted applications.