title: Effects of p-(Trifluoromethoxy)benzyl and p-(Trifluoromethoxy)phenyl Molecular Architecture on the Performance of Naphthalene Tetracarboxylic Diimide-Based Air-Stable n-Type Semiconductors.
abstract: N,N'-Bis(4-trifluoromethoxyphenyl) naphthalene-1,4,5,8-tetracarboxylic acid diimide (NDI-POCF3) and N,N'-bis(4-trifluoromethoxybenzyl) naphthalene-1,4,5,8-tetracarboxylic acid diimide (NDI-BOCF3) have similar optical and electrochemical properties with a deep LUMO level of approximately 4.2 eV, but exhibit significant differences in electron mobility and molecular packing. NDI-POCF3 exhibits nondetectable charge mobility. Interestingly, NDI-BOCF3 shows air-stable electron transfer performance with enhanced mobility by increasing the deposition temperature onto the octadecyltrichlorosilane (OTS)-modified SiO2/Si substrates and achieves electron mobility as high as 0.7 cm(2) V(-1) s(-1) in air. The different mobilities of those two materials can be explained by several factors including thin-film morphology and crystallinity. In contrast to the poor thin-film morphology and crystallinity of NDI-POCF3, NDI-BOCF3 exhibits larger grain sizes and improved crystallinities due to the higher deposition temperature. In addition, the theoretical calculated transfer integrals of the intermolecular lowest unoccupied molecular orbital (LUMO) of the two materials further show that a large intermolecular orbital overlap of NDI-BOCF3 can transfer electron more efficiently than NDI-POCF3 in thin-film transistors. On the basis of fact that the theoretical calculations are consistent with the experimental results, it can be concluded that the p-(trifluoromethoxy) benzyl (BOCF3) molecular architecture on the former position of the naphthalene tetracarboxylic diimides (NDI) core provides a more effective way to enhance the intermolecular electron transfer property than the p-(trifluoromethoxy) phenyl (POCF3) group for the future design of NDI-related air-stable n-channel semiconductor.
authors.affiliation: School of Advanced Materials, Peking University Shenzhen Graduate School, Peking University , Shenzhen 518055, China.
authors.forename: Dongwei
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech) , 30 South Puzhu Road, Nanjing 211816, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.affiliation: School of Advanced Materials, Peking University Shenzhen Graduate School, Peking University , Shenzhen 518055, China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: School of Advanced Materials, Peking University Shenzhen Graduate School, Peking University , Shenzhen 518055, China.
authors.forename: Aiyuan
authors.initials: A
authors.lastname: Li
authors.affiliation: School of Advanced Materials, Peking University Shenzhen Graduate School, Peking University , Shenzhen 518055, China.
authors.forename: Chao
authors.initials: C
authors.lastname: He
authors.affiliation: Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech) , 30 South Puzhu Road, Nanjing 211816, China.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Yu
authors.affiliation: School of Advanced Materials, Peking University Shenzhen Graduate School, Peking University , Shenzhen 518055, China.
authors.forename: Yaowu
authors.initials: Y
authors.lastname: He
authors.affiliation: School of Advanced Materials, Peking University Shenzhen Graduate School, Peking University , Shenzhen 518055, China.
authors.forename: Chaoyi
authors.initials: C
authors.lastname: Yan
authors.affiliation: School of Advanced Materials, Peking University Shenzhen Graduate School, Peking University , Shenzhen 518055, China.
authors.forename: Osamu
authors.initials: O
authors.lastname: Goto
authors.affiliation: School of Advanced Materials, Peking University Shenzhen Graduate School, Peking University , Shenzhen 518055, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Meng
keywords: air-stable; n-type organic semiconductor; naphthalene diimide; organic thin-film transistor; trifluoromethoxy