Fig. 3.
STM images of the trans and cis domain. (A) Constant-current STM image of trans-AZO SAM on Au(111) showing a rectangular unit cell containing two molecules (a = 0.65 ± 0.05 nm, b = 0.89 ± 0.05 nm, and α = 84° ± 5). Average tunneling current (IT) = 55 pA; bias voltage (VT) = 150mV. (B) STM image showing a cis domain of a sample prepared by incubating overnight the Au(111) substrate in solution of 1 under light irradiation at 365 nm. After removal from the incubating solution, the sample was further irradiated for 90 min before imaging. The picture has been recorded ≈30 min after irradiation. IT = 13.22 pA; VT = 280 mV. The arrows indicate the direction of the bending during the switch of each molecule in the domain.