,Electronic states and molecular orientation of ITIC film

• 作 者: Ying-Ying Du De-Qu Lin Guang-Hua Chen Xin-Yuan Bai Long-Xi Wang Rui Wu Jia-Ou Wang Hai-Jie Qian Hong-Nian Li
• 机 构: Department of Physics, Zhejiang University, Hangzhou 310027, China“,”Institute of High Energy Physic
• 出 处: 中国物理B（英文版）
• 发表日期: 2018年8期
• 关键词: electronic states molecular orientation photovoltaic small molecule photoelectro

ITIC is the milestone of non-fullerene small molecule acceptors used in organic solar cells. We study the electronic states and molecular orientation of ITIC film using photoelectron spectroscopy and x-ray absorption spectroscopy. The negative integer charge transfer energy level is determined to be 4.00 ± 0.05 eV below the vacuum level, and the ionization potential is 5.75 ± 0.10 eV. The molecules predominantly have the face-on orientation on inert substrates as long as the surfaces of the substrates are not too rough. These results provide the physical understanding of the high performance of ITIC-based solar cells, which also afford implications to design more advanced photovoltaic small molecules.