Fig. 2: STM topographies and DFT simulations for 17- and 13-polymers.
From: Small bandgap in atomically precise 17-atom-wide armchair-edged graphene nanoribbons
a Large-scale STM image (scanning paremeters: sample bias Vs = 1.1 V, tunneling current It = 10 pA) of 17-polymers on Au(111) and b small-scale image (Vs = 1.1 V, It = 10 pA). Structural model of single 17-polymer is superimposed in b. c DFT simulated image (energy window U = 1.1 eV) of the 17-polymer. d Large-scale STM image (Vs = −1.2 V, It = 70 pA) of 13-polymers on Au(111) and e small-scale image (Vs = 1.0 V, It = 10 pA) together with structural model. f DFT simulated image (U = 1.0 eV) of the 13-polymer. All STM images were taken at 77 K. Scale bar, 10 nm in a, d, 1 nm in b, c, e, f.
