Easily Processable Phenylene−Thiophene-Based Organic Field-Effect Transistors and Solution-Fabricated Nonvolatile Transistor Memory Elements

Abstract

The synthesis of a new series of mixed phenylene-thiophene oligomers is reported; 2,5-bis(4-n-hexylphenyl)thiophene (dH-PTP, 1), 5,5'-bis(4-n-hexylphenyl)-2,2'-bithiophene (dH-PTTP, 2), 5,5' '-bis(4-n-hexylphenyl)-2,2':5',2' '-terthiophene (dH-PT(3)P, 3), 5,5' "-bis(4-n-hexylphenyl)-2,2':5',2' ':5' ',2' "-quaterthiophene (dH-PT(4)P, 4), 1,4-bis[5-(4-n-hexylphenyl)-2-thienyl]benzene (dH-PTPTP, 5), and 2,5-bis[4(4'-n-hexylphenyl)phenyl]thiophene (dH-PPTPP, 6) were characterized by (1)H NMR, elemental analysis, UV-visible spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. Vacuum-evaporated and solution-cast films were characterized by X-ray diffraction and scanning electron microscopy. All compounds display high p-type carrier mobilities as evaporated (up to 0.09 cm(2)/Vs) and as solution-cast (up to 0.03 cm(2)/Vs) films on both Si/SiO(2) and ITO/GR (glass resin) substrates. The straightforwardly synthesized dH-PTTP (2) displays an unprecedented combination of mobility, on/off ratio, stability, and processability. Both dH-PTTP (2) and dH-PPTPP (6) display a reversible, tunable, and stable memory effect even as solution-cast devices, with turn-on characteristics shifting from accumulation mode to zero or depletion mode after a writing voltage V(w) is applied. The charge storage is distributed over the gate dielectric structure and is concentrated near the dielectric-semiconductor interface, as evidenced by the response of "floating gate" configuration devices. Simple nonvolatile elements have been fabricated by solution-only techniques on ITO substrates using spin-coated glass resin, solution-cast oligomeric semiconductors, and painted graphite paste electrodes.

Side-chain effect of organic semiconductors in OFET-based chemical sensors

“…Semiconductors synthesis 5,5'-bis(4-hexylphenyl)-2,2'-bithiophene (6PTTP6) was synthesized according to the previously reported process [41]. The precursor with various alkyl lengths (0, 2 and 12) (bromide benzene, 4-bromo-ethylbenzene and 4-bromo-dodecylbenzene) is used to synthesize 5,5'-diphenyl-2,2'-bithiophene (PTTP), 5,5'-bis(4-ethylphenyl)-2,2'-bithiophene (2PTTP2) and 5,5'-bis(4-dodecylphenyl)-2,2'-bithiophene (12PTTP12).…”

A comprehensive study of the effect of reactive end groups on the charge carrier transport within polymerized and nonpolymerized liquid crystals

“…1 The second set of materials was based on substituted bis͑4-heptylphenyl͒-bithiophene ͑PTTP͒, which has previously been reported to demonstrate high field effect mobilities as a polycrystalline film. 8 The third and final set of materials was based on substituted quaterthiophenes ͑QT͒. Quaterthiophenes were chosen as they had been shown to have excellent field effect mobilities as vacuum deposited thin films, 9 and demonstrate liquid crystalline behavior when substituted with alkyl chains.…”

DFT STUDY ON LOW MOLECULAR WEIGHT α,α-DITERT-BUTYL-4H-CYCLOPENTA[2,1-b,3;4-b'] DITHIOPHENE AND α,α-DITERT-BUTYL-4H-CYCLOPENTA[2,1-b,3;4-b']DITHIOPHENE S-OXIDE BRIDGED DERIVATIVES

“…[1][2][3][4][5][6][7][8][9] However, the synthesis, reactivity as dienes in Diels-Alder reactions, and photochemical and electrochemical behavior of other thiophene-related molecules such as thiophene S,S-dioxide, and thiophene S-oxide have also been investigated. [10][11][12][13][14][15][16][17][18][19][20] The orbital energies and electrochemical properties of thiophene S-oxide monomers have been studied theoretically using MP2/6-31G*.…”