A single ZnO nanowire with intrinsic oxygen vacancies is utilized to fabricate four-contact device with focus ion beam lithography technique. Cathodoluminescent spectra indicate strong near-UV and green emission at both room temperature and low temperatures. Experimental measurement shows the temperature-dependent conductivity of the ZnO nanowire at low temperatures （below 100 K）. The further theoretical analysis confirms that weak localization plays an important role in the electrical transport, which is attributed to the surface states induced by plenty of oxygen vacancies in ZnO nanowire.
The molecular thin films of Rose Bengal （RB） embedded in polymethyl methacrylate matrix are fabricated by using the spin-coating technique. The macroscopic current-voltage （I-V） characterization of the film shows that the RB molecule has two conductance switching states with a high ON/OFF ratio in ambient conditions. The infrared spectra indicate that intermolecular hydrogen bonds can form in the RB thin films after their hydrolysis in air. With the first-principles calculations, we demonstrate that the hydrogen bonds will be destroyed in concomitance with the conformational change when the RB molecule switches to its high-conductance state after applying a voltage.
Three different methods are used to manipulate and control phthalocyanine based single molecular rotors on Au （111） surface： （1） changing the molecular structure to alter the rotation potential; （2） using the tunnelling current of the scanning tunnelling microscope （STM） to change the thermal equilibrium of the molecular rotor; （3） artificial manipulation of the molecular rotor to switch the rotation on or off by an STM tip. Furthermore, a molecular ＇gear wheel＇ is successfully achieved with two neighbouring molecules.
