High-performance air-stable n-channel organic thin film transistors based on halogenated perylene bisimide semiconductors.
The syntheses and comprehensive characterization of 14 organic semiconductors based on perylene bisimide (PBI) dyes that are equipped with up to four halogen substituents in the bay area of the perylene core and five different highly fluorinated imide substituents are described. The influence of the substituents on the LUMO level and the solid state packing of PBIs was examined by cyclic voltammetry and single crystal structure analyses of seven PBI derivatives, respectively. Top-contact/bottom-gate organic thin film transistor (OTFT) devices were constructed by vacuum deposition of these PBIs on SiO(2) gate dielectrics that had been pretreated with n-octadecyl triethoxysilane in vapor phase (OTS-V) or solution phase (OTS-S). The electrical characterization of all devices was accomplished in a nitrogen atmosphere as well as in air, and the structural features of thin films were explored by grazing incidence X-ray diffraction (GIXD) and atomic force microscopy (AFM). Several of those PBIs that bear only hydrogen or up to two fluorine substitutents at the concomitantly flat PBI core afforded excellent n-channel transistors, in particular, on OTS-S substrate and even in air (mu > 0.5 cm(2) V(-1) s(-1); I(on)/I(off) > 10(6)). The best OTFTs were obtained for 2,2,3,3,4,4,4-heptafluorobutyl-substituted PBI 1a ("PTCDI-C4F7") on OTS-S with n-channel field effect mobilities consistently >1 cm(2) V(-1) s(-1) and on-to-off current rations of 10(6) in a nitrogen atmosphere and in air. For distorted core-tetrahalogenated (fluorine, chlorine, or bromine) PBIs, less advantageous solid state packing properties were found and high performance OTFTs were obtained from only one tetrachlorinated derivative (2d on OTS-S). The excellent on-to-off current modulation combined with high mobility in air makes these PBIs suitable for a wide range of practical applications.
Universität Würzburg, Institut für Organische Chemie, Center for Complex Material Systems, Am Hubland, Germany.
Rüdiger
R
Schmidt
Joon Hak
JH
Oh
Ya-Sen
YS
Sun
Manuela
M
Deppisch
Ana-Maria
AM
Krause
Krzysztof
K
Radacki
Holger
H
Braunschweig
Martin
M
Könemann
Peter
P
Erk
Zhenan
Z
Bao
Frank
F
Würthner
D000388:Air; D004396:Coloring Agents / Q000138:chemical synthesis / Q000737:chemistry; D018360:Crystallography, X-Ray; D004563:Electrochemistry; D006846:Hydrocarbons, Halogenated / Q000138:chemical synthesis / Q000737:chemistry*; D007094:Imides / Q000138:chemical synthesis / Q000737:chemistry*; D008567:Membranes, Artificial; D008958:Models, Molecular; D015394:Molecular Structure; D010316:Particle Size; D010569:Perylene / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D012666:Semiconductors; D013237:Stereoisomerism; D013696:Temperature; D014173:Transistors, Electronic
D004396:Coloring Agents; D006846:Hydrocarbons, Halogenated; D007094:Imides; D008567:Membranes, Artificial; C510697:perylene bisimide; D010569:Perylene