Tuning the Energy Level Alignment at the SnPc/Ag(111) Interface Using an STM Tip

The tip influence on the energy level alignment at the SnPc/Ag(111) interface has been addressed via scanning tunneling spectroscopy (STS). A collective effect characteristic for both molecular conformations up and down is reported to shift the corresponding first filled and empty levels toward the Fermi energy via a tip - sample distance decrease. The importance of the tin ion coupling to the metal electrodes is emphasized for the newly reported cross-bending effect as well as for a controllable tip-induced single-molecule switching and nano-writing within densely packed molecular arrays.