Solution Synthesis of N = 8 Armchair Graphene Nanoribbons with High Charge Carrier Mobility

Structurally defined graphene nanoribbons (GNRs) have emerged as promising candidates for nanoelectronic devices. Low bandgap (< 1 eV) GNRs are particularly important when considering the Schottky barrier in device performance. Here, we demonstrate the first solution synthesis of 8-AGNRs through a carefully designed arylated polynaphthalene precursor. The efficiency of the oxidative cyclode-hydrogenation of the tailor-made polymer precursor into 8-AGNRs was validated by FT-IR, Raman, and UV-vis-near-infrared (NIR) absorption spectroscopy, and further supported by the synthesis of naphtho[1,2,3,4-ghi]perylene derivatives (1 and 2) as subunits of 8-AGNR, with a width of 0.86 nm as suggested by the X-ray single crystal analysis. The resulting 8-AGNR exhibited a remarkable NIR absorption extending up to ~2400 nm, corresponding to an optical bandgap as low as ~0.52 eV. Moreover, optical-pump TeraHertz-probe spectroscopy revealed a charge-carrier mobility in the dc limit of ∼270 cm2 V–1 s–1 for the 8-AGNR