Versatile Pendant Polymer for Selective Charge Carrier Transport via Controlling the Supramolecular Self‐Assembly

Abstract

Polyvinyl carbazole (P0)-based pendant polymers were synthesized by modifying carbazole motifs with pyrene derivatives (P1 and P4) to manipulate the bandgap and frontier orbital energy levels. To establish the electronic properties of pendant polymers according to structural differences, the polymers were utilized as additional hole transport layers in planar-type perovskite solar cells and organic photovoltaic cells. When P4 with thiophene-pyrene pendant was used as hole transport layer, all device parameters, except open-circuit voltage, were significantly improved in comparison with P0 and P1 (conjugated with t-butyl pyrene derivatives). Since P4 had more electrically conductive thiophene units than benzene units with fewer alkyl groups, the supramolecular assembly of P4 was found to be more favorable in electronic devices. Furthermore, devices with P4 demonstrated lower dark current than others, which could potentially be useful for charge carrier transport and sensitive photo detecting devices.

Stereoregular pendant electroactive polymers with extended pendants via post‐polymerization copper catalyzed azide‐alkyne cycloaddition

“…It is expected that the increased steric demand of the extended pendant group in P5 , particularly due to the branched side‐chains, is likely preventing optimal stacking of the π ‐system for hole transport at this particular fixed spacer length which could serve as one possible explanation for the decrease in mobility. Such adverse π–π interactions have previously been reported by Wang et al for similar 3,6‐disubtituted carbazoles as electroactive pendant groups in atactic non‐conjugated polymers as a result of the substituent containing sterically demanding t Bu‐groups 51 …”

“…Such adverse π-π interactions have previously been reported by Wang et al for similar 3,6-disubtituted carbazoles as electroactive pendant groups in atactic non-conjugated polymers as a result of the substituent containing sterically demanding tBu-groups. 51…”

Relating Structure to Properties in Non‐Conjugated Pendant Electroactive Polymers

“…Rather than focusing on tacticity effects, Wang et al restricted themselves to atactic backbones in a 2021 study that investigated the effect of varying the pendant group itself on the electronic properties, in particular bandgaps, frontier orbital energies, and hole transporting abilities, of the resulting polymers by post-polymerization 3,6-disubstitution of commercially available PVK. [91] A bis-tBu-pyrenyl and a bis-pyrenyl-thiophenyl derivative of PVK, poly(bis-tBu-pyrenyl-VK) and poly(bis-pyrenylthiophenyl-VK), shown in Figure 4a, were synthesized.…”

High‐Sensitivity Organic Photodetector Based on Surface‐Concentrated Nonfused Ring Electron Acceptor

“…The energy levels of the TPDC-4F together with the other layers such as PEDOT:PSS, PM6, PDINN used in the OPD are shown in Figure 1b. [24][25][26] The energy level of the TPDC-4F is determined by cyclic voltammetry (CV) using the Ag/AgCl reference electrode (Figure S1, Supporting Information). From the CV curves, the lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) energy levels were calculated as −5.83 and −3.99 eV, respectively, according to the equation of E HOMO /E LUMO = −e(E ox /E red + 4.80) (eV).…”