Solution-processable fluorene derivative for organic thin-film transistors

Small-molecule ambipolar transistors

“…Indeed, further π-extension utilizing a dimer unit ( C4T , Fig. 9) 303 and DA units ( TCNAQ , 304 BTFM-1 , and BTFM-2 ) 305 leads to ambipolar properties. The former compound, C4T , is regarded as a cross-conjugated 4T skeleton with a wider HOMO–LUMO gap (∼2.0 eV) than that of the linear-conjugated Q4T (∼1.3 eV).…”

“…303 In the latter compounds, TCNAQ and BTFM, the ambipolar transport is realized by a delicate balance of the strength of the electrondonating/accepting abilities of the DA parts; the biphenyl analogue of TCNAQ instead of the bithiophene unit shows electron-only transport, 304 and the carbonyl analogues of BTFM instead of the dicyanomethylene group show unipolar pchannel transport. 305 On the other hand, cross-conjugated five-fused-ring systems have an ambipolar nature without p-extension and dicyanomethylene substitution, as demonstrated in s-indaceno[1,2b:5,6-b 0 ]dithiophene derivatives (IDT-1 and IDT-2, Fig. 9).…”

Flexible organic optoelectronic devices on paper

“…As a variable current switch, the transistor can control the output current based on the input voltage. Organic thin-film transistors (OTFTs) have been demonstrated an excellent performance ( Deng et al., 2021 ; Kim et al., 2020 , 2021 ; Lu et al., 2020 ; Makita et al., 2021 ).…”

Liquid crystal phase of counter-rotating staircases – A case of antiferrochirality

“…With conjugated fluorophore cores, FCN16 and FO16 are potential electroptic materials 36,37 . Their UV-vis and fluorescence spectra are shown in Fig.…”