[8p-N306-1~20] 12.2 Characterization and Materials Physics

3:15 PM - 3:30 PM JST(6:15 AM - 6:30 AM UTC)

[8p-N306-7] Relationship between electron affinity and exciton binding energy for organic light-emitting diode materials studied by low-energy inverse photoelectron spectroscopy

〇(M1)Ota Nagaoka¹, Kazuki Nakano¹, Kiyoshi Torizuka¹, Hiroyuki Yoshida^1,2 (1.Chiba Univ., 2.Chiba Univ.)

Keywords:

organic semiconductor,low-energy inverse photoemission spectroscopy(LEIPS),electron affinity

We have previously investigated the exciton binding energy of solar cell materials and general organic semiconductors using low-energy inverse photoelectron spectroscopy, and proposed that exciton binding energy is about one-fourth of the transport gap. In this study, we precisely measured the electron affinity of organic light-emitting materials and examined the exciton binding energy and the transport gap. Although the exciton binding energycan generally be expressed as a linear relation with the transport gap with a slope of about 1/4, significant variation was observed. We investigated crystallization and spontaneous polarization as possible causes of this variation.