Multifunctional Benzo[4,5]thieno[3,2-b]benzofuran Derivative with High Mobility and Luminescent Properties

Abstract

Development of multifunctional materials and devices has garnered enormous attention in the field of organic optoelectronics; nevertheless, achieving high mobility together with strong luminescence in a single semiconductor remains a major bottleneck. Here, a new multifunctional semiconductor molecule, 2,7-diphenylbenzo­[4,5]­thieno­[3,2-b]­benzofuran (BTBF-DPh), that integrates high charge transporting [1]­benzothieno­[3,2-b]­[1]­benzothiophene with a strongly emissive furan group, is synthesized and applied in three types of optoelectronic devices, including organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs), and organic phototransistors (OPTs). OLEDs based on BTBF-DPh as the emissive layer showed a blue emission with CIE coordinates of (0.151, 0.069) and a maximum current efficiency of 2.96 cd A–1 with an external quantum efficiency of 4.23%. Meanwhile, OFETs fabricated with BTBF-DPh thin film manifested a carrier mobility of 0.181 cm2 V–1 s–1, which is comparable to that of thiophene-based counterparts. Additionally, BTBF-DPh-based OPTs exhibited a maximum responsivity and detectivity of 2.07 × 103 A W–1 and of 5.6 × 1015 Jones, respectively. On the one hand, our rationally designed material, BTBF-DPh, has a dense and close-packed structure with an extended π-conjugation, facilitating charge transport through adjacent molecules. On the other hand, the weakened dipole–dipole interactions between BTBF-DPh molecules that resulted from the unambiguous J-aggregation and reduced spin–orbit coupling caused by replacing sulfur atom significantly suppress the exciton quenching, contributing to the improved photoluminescence performance. These results validate that our newly developed BTBF-DPh is a promising multifunctional organic semiconductor for optoelectronic devices.

Modulating the Alkylation Position on Terminal Thiophene Ring of Naphtho[2,3-b:6,7-b′] Bithieno[2,3-d] Thiophene (NBTT) for High-Performance Organic Optoelectronic Devices

“…With the increasing of the intensity of the irradiation light, the more photogenerated carriers are excited, which would further fill the interface trap leading to the device easily turn-on and cause the threshold shift to the positive voltage. As a result, the optical figures of merit including photosensitivity ( P ) of 2.0× 10 8 , photoresponsivity ( R ) of 3.3 × 10 3 A/W, and detectivity ( D *) of 1.3 × 10 16 Jones were achieved (Figure b and Figure S16b–d), which are among the best values for thienoacene-based phototransistors. ,,− For 3,9-C8NBTT-based phototransistors (Figure c and Figure S17a), the device displayed lower performance metrics with P of 8.5× 10 7 , R of 7.0 × 10 2 A/W, and D * of 2.8 × 10 15 Jones under illumination wavelength of 405 nm, possibly due to the lower carrier transport performance as compared with 2,8-C8NBTT (Figure d and Figure S17b–d). NBTT, as the molecule of the lowest mobility within this series, exhibited even lower values of P , R , and D * by at least 1 order of magnitude in OPT devices (Figure S18).…”

Conjugated branch modulated optical characteristics of multibranched push–pull molecules composed of quinoxaline and triphenylamine groups: transition of the conjugated branch from unusual effects to usual effects

“…In addition, the third component corresponds to the decay process from the HLCT′ state to the ground state. 49,50 Apparently, the enhancement of solvent polarity changes the relaxation mechanism of QTPA1, which can be responsible for its variance in Stokes shift as a function of Δ f (in Fig. 1(D)).…”

Multifunctional Heteropentalenes: From Synthesis to Optoelectronic Applications

“…The same aggregation type can be also found for other benzo-fused TTs, such as BTBT, DNTT, and DATT (see Figures 3 and 5 ). 15d , 92 For oligomer 32 , the solid-state spectrum is broadened and contains red-shifted features because the interacting molecules form both H- and J-aggregates in the solid state caused by herringbone and slipped π–π interactions, respectively ( Figure 12 D). The fully fused oligomer 33 displays a relatively small blue-shift in its solid-state spectrum and adopts a π-stacked packing motif ( Figure 12 E).…”