Long-term Stability of Atomically Precise Graphene Nanoribbon Transistors

Transistors must continuously evolve and improve to sustain high performance and energy-efficient computing, especially to meet the energy and performance demanding AI systems. Transistors fabricated with silicon as the dominant channel materials for more than half a century are struggling to keep the pace with these ever-growing requirements, necessitating new transistor channel materials capable of delivering significantly improved performance and energy efficiency compared to silicon.

Bottom-up synthesized atomically precise graphene nanoribbons (GNRs) are a promising a highly promising alternative to silicon for transistor channel materials in next-generation electronic devices. This class of 2D van der Waals materials have a tunable electronic structure and high theoretical mobility. Despite the immense potential, the long-term stability and reliability of GNRs have not been thoroughly investigated over a long time period. This is a crucial step necessary for establishing the foundation for the practical application and large-scale integration of GNR field-effect transistors (GNRFETs). In this work, we studied the long-term stability of GNRs in terms of electrical performance, structural integrity, and surface chemistry. We fabricated short channel field effect transistors (FETs) using bottom-up synthesized 9-atom wide armchair GNRs (9-AGNRs) with a local backgate geometry. We comprehensively characterized the GNRs and the FET devices through electrical transport measurements, Raman spectroscopy (wavelength of 785 nm), and atomic force microscopy (AFM) ) to determine the performance and stability of GNRs over several months in air. We will discuss potential improvements in device performance and long-term stability.