Group IV Graphane Analogues As Electronic Materials

Here, we will describe our recent development of the electronic properties, a new family of two-dimensional (2D) materials based on honeycomb, sp³-hybridized Group IV elements. These ligand-terminated Si, Ge, and Sn “graphane analogues” are an intriguing class of 2D materials that offer the potential to tailor the structure, stability, and properties via covalent chemistry.  The electronic structure of these materials can be systematically controlled by attaching different surface terminating ligands, and even bestowing properties that don’t exist in the normal three-dimensional structure.  For example, with the appropriate surface functionalizing ligand, these 2D materials feature direct band gaps, enhancing silicon and germanium’s performance in photovoltaics, photodetectors, light-emitting diodes, and lasers.    These materials can be synthesized in gram-scale quantities, exfoliated as single-layers, and prepared as thin layers directly on Si and Ge wafers.   Additionally, we will describe our recent studies on controlling the electronic behavior by doping the lattice with Group III and Group V elements.  This class of two-dimensional materials are not only promising building blocks for a variety of conventional semiconductor applications, but also provides a pioneering platform to systematically and rationally control material properties using covalent chemistry.