[18a-Z23-1~11] 12.2 Characterization and Materials Physics

[18a-Z23-3] Exciton Binding Energy of Organic Semiconductors

〇Hiroyuki Yoshida^1,2, Ai Sugie³, Kosuke Terado³, Kyohei Nakano⁴, Keisuke Tajima⁴, Itaru Osaka⁵ (1.Chiba Univ., 2.MCRC Chiba Univ., 3.Chiba Univ, 4.RIKEN, 5.Hiroshima Univ.)

Keywords:organic semiconductor, exciton binding energy, low energy inverse photoelectron spectroscopy

Owing to the low dielectric constants, the exciton binding energy of organic semiconductor is large and often exceeds 0.5 eV. It is therefore crucial to determine precisely their values. In this work, we determined the exciton binding energies of more than 30 materials for organic solar cells using combination of low-energy inverse photoelectron spectroscopy, ultraviolet photoelectron spectroscopy and photoemission yield spectroscopy as well as the optical transitions. Based on the determined values, we will discuss strategy for controlling the exciton binding energy of organic semiconductors.