[21p-231C-1~10] 12.2 Characterization and Materials Physics

[21p-231C-1] Impact of the molecular quadrupole moment in the molecularly mixed film of organic semiconductors

〇Yuki Uemura¹, abdullah syed¹, Hiroyuki Yoshida^1,2 (1.Chiba Univ., 2.Chiba Chirality)

Keywords:organic semiconductor

It has been reported that the electronic levels of organic semiconductor can be tuned continuously by changing the mixing ratio of two molecules having opposite quadrupole moments. In this study, we applied ultraviolet photoelectron and low energy inverse photoemission spectroscopies to a co-deposited film of copper phthalocyanine and its fluorinated compound which have the opposite permanent quadrupole moments. We have successfully determined the energy of the electrostatic and induction effects based solely on the experimental data. The result indicates that the electrostatic effect causes the continuous shift of the energy levels. Since the leading term of the electrostatic energy is the charge - quadrupole interaction, the importance of molecular quadrupole is also highlighted.