A Soluble Dynamic Complex Strategy for the Solution‐Processed Fabrication of Organic Thin‐Film Transistors of a Boron‐Containing Polycyclic Aromatic Hydrocarbon

Abstract

The solution-processed fabrication of thin films of organic semiconductors enables the production of cost-effective, large-area organic electronic devices under mild conditions. The formation/dissociation of a dynamic B-N coordination bond can be used for the solution-processed fabrication of semiconducting films of polycyclic aromatic hydrocarbon (PAH) materials. The poor solubility of a boron-containing PAH in chloroform, toluene, and chlorobenzene was significantly improved by addition of minor amounts (1 wt % of solvent) of pyridine derivatives, as their coordination to the boron atom suppresses the inherent propensity of the PAHs to form π-stacks. Spin-coating solutions of the thus formed Lewis acid-base complexes resulted in the formation of amorphous thin films, which could be converted into polycrystalline films of the boron-containing PAH upon thermal annealing. Organic thin-film transistors prepared by this solution process displayed typical p-type characteristics.

Doping Polycyclic Aromatics with Boron for Superior Performance in Materials Science and Catalysis

“…The transfer and output curves of a corresponding organic field‐effect transistor are indicative of p‐type modulation . One particularly remarkable example of a p‐type OFET has been found, in which the peculiar features of its boron dopant atom have not only been used to imprint the desired electronic properties on the parent PAH, but also to facilitate the fabrication of the device by cost‐efficient spin‐coating from precursor solutions: trinaphthylborane 8 (Scheme ) is poorly soluble in common organic solvents as a result of its planar molecular structure, which promotes the formation of densely π‐stacked columnar aggregates. As mentioned above, the addition of pyridine generates the four‐coordinate boron‐nitrogen adduct 8⋅ Py and induces a plane‐to‐bowl conversion of the B‐PAH skeleton, thereby disfavoring intermolecular π‐interactions.…”

Fully fused boron-doped polycyclic aromatic hydrocarbons: their synthesis, structure–property relationships, and self-assembly behavior in aqueous media

“… 11 Moreover, their labile complexation ability with Lewis bases has not only led to the emergence of intriguing thermochromism and dual-emission properties, 4,6 b but has also been utilized for solution-processing thin-film fabrication of insoluble π-electron materials. 12 These findings have increased the potential utility of this compound class and therefore promoted the exploration of their chemical space.…”

Boron-Doped Polycyclic π-Electron Systems with an Antiaromatic Borole Substructure That Forms Photoresponsive B–P Lewis Adducts

“…Owing to their structural constraints, this class of molecules is stable in the presence of air and water despite the absence of steric protection . Furthermore, the lack of steric protection endows such boron-doped PAHs not only with the ability to undergo π-stacking but also with a Lewis acidity that allows the formation of Lewis acid–base complexes, even with neutral Lewis bases such as pyridine. − Importantly, the dynamic complexation of these Lewis acidic π-systems with an appropriate Lewis base can be used to produce specific functionality, for example, thermochromism, chemisorption, dual emissions derived from photodissociation, , thin-film processing of poorly soluble materials, and control over self-assembly processes . However, as the accessible range of Lewis acidity for such hexagonal boracycle-based polycyclic π-systems is narrow, this has restricted the Lewis bases available for these systems to almost exclusively pyridine and other amines, and this limitation has hampered the expansion of this chemistry.…”