[17p-E402-1~9] Organic Semiconductor Devices: Present, Past, and Future: Focusing on Photovoltaic Conversion

[17p-E402-2] Conduction band structure and electron transport mechanism of organic semiconductors

〇Hiroyuki Yoshida^1,2 (1.Chiba Univ., 2.MCRC, Chiba Univ.)

Keywords:organic semiconductor, electronic band structure, polaron

The energy band structure (the momentum-energy relation) provides crucial information on charge transport behavior in organic semiconductors. We have developed angle-resolved low-energy inverse photoelectron spectroscopy to reveal the conduction band structure of organic semiconductors. The derived bandwidths from the LUMO are substantially smaller than those predicted by density functional theory calculations. To reproduce this bandwidth reduction, we propose an improved (partially dressed) polaron model. The present results demonstrate that electron mobility in high-mobility organic semiconductors is indeed limited by polaron formation.