Naphthalenetetracarboxylic Diimide-Based n-Channel Transistor Semiconductors:  Structural Variation and Thiol-Enhanced Gold Contacts

Abstract

The synthesis and field-effect transistor (FET) electron mobility of ten N-substituted naphthalene 1,4,5,8-tetracarboxylic diimide (NTCDI) derivatives deposited at ambient and elevated temperatures are reported. Mobilities >0.01 cm 2 /(V s) were measured in air for three NTCDIs with partially fluorinated substituents, and >0.001 cm 2 /(V s) for a hydroxy-terminated compound. Mobilities 0.001−0.1 cm 2 /(V s) were also found for three n -alkyl NTCDIs, but only under vacuum; FET operation with gold bottom contacts was enabled by specific thiol coatings of the contacts. The highest mobility in air, >0.1 cm 2 /(V s), was conferred by 4-trifluoromethylbenzyl substitution, while 1 H,1 H -perfluorooctyl substitution resulted in an on/off ratio in air >10 5 . Solution electrochemistry and solid-state X-ray and electron diffraction were employed to partially explain the results, and applications of the materials to complementary circuits are considered.