Synthesis and structural analysis of dimethylaminophenyl-end-capped diketopyrrolopyrrole for highly stable electronic devices with polymeric gate dielectric

The synthesis and structural analysis of DPP(PhNMe₂)₂, a stable diketopyrrolopyrrole derivative end-capped with a strongly electron-donating dimethylaminophenyl moiety is reported and the origin of ambient stability is analyzed in detail.

Grain Boundary Induced Bias Instability in Soluble Acene-Based Thin-Film Transistors

Since the grain boundaries (GBs) within the semiconductor layer of organic field-effect transistors (OFETs) have a strong influence on device performance, a substantial number of studies have been devoted to controlling the crystallization characteristics of organic semiconductors. We studied the intrinsic effects of GBs within 5,11-bis(triethylsilylethynyl) anthradithiophene (TES-ADT) thin films on the electrical properties of OFETs. The GB density was easily changed by controlling nulceation event in TES-ADT thin films. When the mixing time was increased, the number of aggregates in as-spun TES-ADT thin films were increased and subsequent exposure of the films to 1,2-dichloroethane vapor led to a significant increase in the number of nuleation sites, thereby increasing the GB density of TES-ADT spherulites. The density of GBs strongly influences the angular spread and crystallographic orientation of TES-ADT spherulites. Accordingly, the FETs with higher GB densities showed much poorer electrical characteristics than devices with lower GB density. Especially, GBs provide charge trapping sites which are responsible for bias-stress driven electrical instability. Dielectric surface treatment with a polystyrene brush layer clarified the GB-induced charge trapping by reducing charge trapping at the semiconductor-dielectric interface. Our study provides an understanding on GB induced bias instability for the development of high performance OFETs.

Facile synthesis of arylthiophenyl-functionalized diketopyrrolopyrrole derivatives via direct C–H arylation: characterization and utilization in organic electronic devices

We report the synthesis and characterization of three arylthiophenyl-functionalized diketopyrrolopyrrole derivatives with different end-capping groups via direct C–H arylation.

Laterally-stacked, solution-processed organic microcrystal with ambipolar charge transport behavior

We report the formation of laterally stacked ambipolar crystal wire for high-mobility organic field-effect transistors (OFETs), along with a simple logic circuit through a solution process. A soluble pentacene derivative, 6,13-bis(triisopropylsilylethynyl)pentacene (Tips-pentacene), and N,N'-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) were used as p-type and n-type organic semiconductors, respectively. The laterally stacked ambipolar crystal wire is made up of Tips-pentacene and PTCDI-C8 crystals in a structure of Tips-pentacene/PTCDI-C8/Tips-pentacene (TPT). The inner part of the crystal is made up of PTCDI-C8, and Tips-pentacene is present on both sides. These TPT crystals exhibit typical ambipolar charge transport behavior in organic electronic devices, which show very balanced hole and electron mobility as high as 0.23 cm(2)/V·s and 0.13 cm(2)/V·s, respectively. Static and dynamic operational stability of the device is investigated by measuring the device performance as a function of storage time and applying voltage pulse, respectively, and it shows good air stability. In addition, a simple logic circuit based on the TPT crystal wire has been fabricated, and the static and dynamic performance has been evaluated. The results indicate that the TPT crystals are potentially useful for miniaturized organic electronic devices.

n-Type small aromatic core diimides flanked with electron donating thienylethyl moieties and electrical responses in organic devices

Synthesis and electrical characteristics of two new n-type small aromatic core diimide derivatives functionalized with an electron donating moiety are reported.