Ladder‐type Heteroarenes: Up to 15 Rings with Five Imide Groups

Abstract

A series of novel imide-functionalized ladder-type heteroarenes with well-defined structure and controllable conjugation lengths were synthesized and characterized. The synthetic route shows remarkable efficacy for constructing the electron-deficient ladder backbones. π-Conjugation extension leads to narrowed band gaps with enhanced electron affinities. The ladder arenes are incorporated into organic thin-film transistors, and show encouraging electron mobilities of 0.013-0.045 cm V s . The heteroarenes reported here provide a remarkable platform for fundamental physicochemical studies and materials innovation in organic electronics.

Triimide‐Functionalized n‐Type Polymer Semiconductors Enabling All‐Polymer Solar Cells with Power Conversion Efficiencies Approaching 9%

“…Figure shows the chemical structures of two new polymer semiconductors f‐BTI3‐T and f‐BTI3‐FT based on the triimide‐functionalized fused arene f‐BTI3, which was designed and synthesized by us before . To promote n‐type performance and suppress p‐type character, the triimide acceptor unit f‐BTI3 is copolymerized with the donor co‐unit having minimal thiophene number, i.e., monothiophene and difluorothiophene.…”

Effects of Bithiophene Imide Fusion on the Device Performance of Organic Thin‐Film Transistors and All‐Polymer Solar Cells

“…[22] In contrast to thieno [3,4-c]pyrrole-4,6-dione (TPD), [7] the open b positions of BTI enable core modification and backbone extension. [24] Among them, the f-BTI2 showed the highest m e value of 0.05 cm 2 V À1 s À1 in OTFTs.T he results clearly demonstrate that f-BTI2 is an excellent building block for high-performance n-type semiconductors.R ecently,B eaujuge and co-workers reported aT PD-3,4-difluorothiophene copolymer, which showed encouraging all-PSC performance with aP CE of 4.4 %a nd a V oc value of 1.1 Vw hen blended with the polymer donor PTB7-Th. [23] Furthermore, aseries of fused BTI oligomers,BTI-BTI5, with different pconjugation lengths were synthesized.…”

“…Thep olymers f-BTI2-FT and s-BTI2-FT ( Figure 1) have similar structures,b ut differ in the linkage between the two BTI units.I nf-BTI2-FT,two BTI moieties are fused to form al adder-type structure, [24] whereas in s-BTI2-FT,t wo BTI moieties are connected by as ingle s bond to form an ew acceptor unit s-BTI2 (see the Supporting Information for the synthesis of monomers and polymers). Then ormalized UV/ Visabsorption spectra of f-BTI2-FT and s-BTI2-FT are shown in Figure 2a.s-BTI2-FT exhibits light absorption in the visible range (400-630 nm) with an absorption onset at 627 nm, resulting in an optical band gap (E g opt )o f1 .98 eV in the film (see Table S1 in the Supporting Information).…”

Imide‐Functionalized Polymer Semiconductors

“…The unique geometry and physicochemical properties of TzTI enables the development of all‐acceptor type homopolymers, and the resulting polymer 68 based on the TzTI dimer exhibited a remarkable unipolar μ e,OTFT of 1.61 cm 2 V −1 s −1 , low off‐currents ( I off ) of 10 −10 –10 −11 A, and substantial current I on / I off ratios of 10 7 –10 8 in OTFT devices . A series of fused BTI‐based ladder‐type small molecular heteroarenes (BTI1‐5) with up to 15 rings and 5 imide groups were also synthesized . With the incorporation of multiple imide groups and all‐acceptor type polymer backbones, a series of semiladder‐type polymer semiconductors based on these imide‐functionalized heteroarenes exhibited unipolar electron transporting properties.…”