INELASTIC ELECTRON-TUNNELING SPECTROSCOPY AND OPTICAL CHARACTERIZATION OF TMPD ADSORBED C(N) TCNQ LANGMUIR-BLODGETT-FILMS

To investigate the effect of alkyl chain length and adsorption time on the charge-transfer complex formation, ultraviolet-visible absorption and inelastic electron tunneling (IET) spectroscopy measurements were carried out for the tetramethylphenylenediamine (TMPD; donor molecule ) adsorbed dodecyl-, pentadecyl- and octadecyl-tetracyanoquinodimethan e (TCNQ) Langmuir-Blodgett (LB) films. In the optical absorption spect ra, the main peak of LB films shows a red-shift depending on alkyl cha in length and adsorption time. Furthermore, the dependence on alkyl ch ain length and adsorption time are also shown in the IET spectra. Thes e results demonstrate that adsorption LB methods enable to control the adsorption ratio of functional molecules and the CT complex formation .