Field-Effect Transistors Based on Networks of Highly Aligned, Chemically Synthesized N = 7 Armchair Graphene Nanoribbons

Abstract

We report on the experimental demonstration and electrical characterization of N = 7 armchair graphene nanoribbon (7-AGNR) field effect transistors. The back-gated transistors are fabricated from atomically precise and highly aligned 7-AGNRs, synthesized with a bottom-up approach. The large area transfer process holds the promise of scalable device fabrication with atomically precise nanoribbons. The channels of the FETs are approximately 30 times longer than the average nanoribbon length of 30 nm to 40 nm. The density of the GNRs is high, so that transport can be assumed well-above the percolation threshold. The long channel transistors exhibit a maximum ION/IOFF current ratio of 87.5.

Atomically precise graphene nanoribbons: interplay of structural and electronic properties

“…Optical images and Raman maps showed high uniformity over areas of square millimetres for transferred GNR films. However, the average length of the CVDsynthesized ribbons (around 10 nm) is significantly shorter than the one obtained for UHV-synthesized ribbons of various types (between 20 and 45 nm 77,249,250 ). A comparison of UHV-and CVD-synthesized GNR FETs shows better performance for the ones containing UHV-synthesized ribbons, likely due to the difference in length.…”

Optimized Substrates and Measurement Approaches for Raman Spectroscopy of Graphene Nanoribbons

“…Highly aligned arrays of GNRs are important to control device properties and can significantly increase device yield as well as the drain current in the transistor "on" state which is essential to meet the demands of switching applications. [24] In a second step, GNRs are transferred from the Au(788) growth substrate onto the RO substrate using an electrochemical delamination (Figure 1b). [25] This method preserves the uniaxial GNR alignment upon substrate transfer and thus allows for a well-defined orientation of the ribbons with respect to the device electrodes.…”

Modified Engineering of Graphene Nanoribbons Prepared via On‐Surface Synthesis

“…The fabricated FET devices based on GNRs exhibited a hole mobility and an on/off current ratio ( I on / I off ) of 0.26 cm 2 V −1 s −1 and 88 (Figure b,c), respectively. Recently, an investigation explored by Passi et al also showed the comparative I on / I off of 87.5 in FET devices based‐on 7‐AGNRs (Figure d) . In order to further improve the performance of GNRs, Llinas et al prepared the AGNR‐based FETs with a short channel (≈20 nm) .…”

“…d) Transfer characteristics of FET devices based on AGNRs at varying drain–source bias and the inset showing the histogram of on/off current ratios for different devices. Reproduced with permission . Copyright 2018, American Chemical Society ( https://doi.org/10.1021/acsami.8b01116).…”