Low-Temperature-Processible, Transparent, and Air-Operable n-Channel Fluorinated Phenylethylated Naphthalenetetracarboxylic Diimide Semiconductors Applied to Flexible Transistors

Abstract

New N, N′-disubstituted-1,4,5,8-naphthalene tetracarboxylic acid diimides (NTCDI) with fluorinated phenylethyl groups were synthesized. In particular, N,N′-bis(2-(pentafluorophenyl)ethyl)-1,4,5,8naphthalene tetracarboxylic acid diimide (5FPE-NTCDI) showed high electron mobility, more than 0.1 cm 2 /(V s) in air, even though the film was deposited at room temperature. The correlation of the crystallinity, morphology, and mobility with the substrate temperature during deposition (T sub ) was studied using X-ray diffraction (XRD) and atomic force microscopy (AFM). The films of 5FPE-NTCDI exhibited a "thin film phase", mixed phase, and crystal bulk phase as T sub was increased. The mixed phase on an octadecyltrimethoxysilane (OTS)-treated substrate also has high electron mobility due to well connected long fiber-shaped grains. The high mobility at low T sub has enabled fabrication of flexible transistors on the clear plastic substrate poly(ethylene terephthalate) (PET). The highest mobility for a flexible, transparent transistor was 0.23 cm 2 /(V s), obtained with low hysteresis.

Self‐Assembling Aryl‐Naphthalendiimide Derivatives with a Nitroxide Radical

“…The low mobility of 4 may be a result of the undesirable packing of the molecules in its crystal (see above) for carrier mobility compared with those of the NDI derivatives with fluoroalkyl [10] or fluorinated phenylethyl substituents. [11] Similar FET characteristics to that of 4 were also recorded for 5, 6, and 7 ( Figures S9-11 in the Supporting Information) with mobilities of the order of 10 À7 cm 2 V À1 s À1 (Table 2). At the same time, it was clarified that the mobilities and on/off ratios are higher for tri-and pentafluorophenyl derivatives 6 and 7 than those of phenyl and 4-fluorophenyl derivatives 4 and 5, which suggests the contribution of the electron-accepting nature of the perfluoro substituents to some extent.…”

Field-effect-tuned lateral organic diodes

“…The lateral organic diode consists of a hole-transporting polymer poly (3-hexylthiophene) (P3HT) (supplied by Plextronics, Inc.) and a derivative of an electron-transporting small molecule, a naphthalene tetracarboxydiimide (NTCDI) (20), as shown schematically in Fig. 1A.…”

Recent Progress in n‐Channel Organic Thin‐Film Transistors

“…Letizia et al [44] have synthesized a new class of soluble oligothiophenes for n-channel OTFTs; the devices exhibited very high electron mobilities up to 0. 51 for solution-cast films. Yoon et al [45] have produced a series of fluoroarene-thiophene oligomers as n-channel semiconductors, and n-channel mobilities as high as 0.5 cm 2 V À1 s À1 with I on /I off > 10 8 (where I on /I off represents the ratio of on current to off current) is achieved for a fluoroarene-thiophene oligomer.…”

“…In 2008, See et al [50] used a one-step synthesis to develop new naphthalene tetracarboxylic diimide semiconductors resulting in excellent performance in air; the largest electron mobility of 0.57 cm 2 V À1 s À1 is competitive with the best air-stable n-channel materials to date. More recently, Jung et al [51] have synthesized new N,N 0 -disubstituted NTCDIs with fluorinated phenylethyl groups, and particularly flexible, transparent transistors with high electron mobilities up to 0.23 cm 2 V À1 s À1 in air were fabricated on the clear plastic substrate poly(ethylene terephthalate) (PET).…”