UC Berkeley

With semiconductor electronics steadily scaling down to nanometer dimensions, the increasing demand for enhanced device performance and energy efficiency necessitates the exploration of novel materials and device mechanisms. A fundamental shift towards constructing electronic components at the molecular level becomes imperative to match this demand while aligning the semiconductor industry’s standards for precision and miniaturization. The emergence of bottom-up synthesized graphene nanoribbons (GNRs) presents an opportune solution within this new paradigm, offering tunable electronic properties enabled by atomically precise synthesis from molecular precursors. GNRs hold the potential to improve prevailing semiconductor technology but also lay the groundwork for pioneering transformational electronics based on tunneling devices and spintronics. This dissertation explores new methodologies, synthetic techniques, and designs aimed at customizing electronic and spin properties in GNRs for diverse next-generation device architectures. In chapter 1 of this dissertation, an overview of the existing synthetic techniques utilized in GNR fabrication and their integration into transistors and sensors are presented. Chapter 2 describes a novel approach to systematically incorporate spin states in GNRs for spintronic applications. Chapter 3 showcases the profound changes in electronic properties achieved through heteroatom core doping, presenting implications for improving current devices. Chapter 4 outlines a conceptual framework for engineering magnetic order in GNRs and nanographenes, marking the initial step towards constructing diverse spin-embedded components within novel device architectures. Finally, chapter 5 delineates a methodology for accessing metallic GNRs, a crucial component for realizing next generation tunneling devices.