N,N-bis(9H-fluoren-9-ylidene)benzene-1,4-diaminedeposited onto highly oriented pyrolyticgraphite (HOPG)was investigated
by contact angle measurement(CAM), Raman spectroscopy and tunneling spectroscopy. The results of CAM and Raman spectra have confirmed that organic layers had deposited on substrate. Tunneling spectra obtained in the scanning tunneling microscopy measurement system were reported as a function of electrode potential. The tunneling current data were acquired at different electrode–electrode separations and depicted significant trend under the action of electric field. Under weak electric fields, the electrode–electrode separation has little effect on the potential of conductance peak. However, with the shrinkage of electrode–electrode separation, the electron transportmodel obeys theOhmic law