[16p-B6-1~23] 12.2 Characterization and Materials Physics

6:15 PM - 6:30 PM JST(9:15 AM - 9:30 AM UTC)

[16p-B6-19] On the Simultaneous Control of Work Function and Energy Levels
by Ion-Modulated Radical Doping for Spiro-OMeTAD

Masaya Kawashima¹, Tiankai Zhang², Feng Wang², Feng Gao², Matz Fahlman², 〇Hiroyuki Yoshida^1,3 (1.Chiba Univ., 2.Linkopings Univ., 3.MCRC-Chiba Univ.)

Keywords:

Hubbard model,ionic salt,perovskite solar cell

Spiro-OMeTAD is a standard hole-collecting layer used in high-efficiency perovskite solar cells. Recently, it has been reported that the work function can be controlled independently of the HOMO level by adding ionic salts. In this study, Hubbard U, the on-site Coulomb repulsion energy of the molecule, was measured from the energy difference between SUMO (singly unoccupied molecular orbital) and SOMO (singly occupied molecular orbital). It turned out that the Hubbard U decreased by 0.6 eV with the addition of ionic salts. This result reveals a mechanism by which the work function can be controlled.