Impact of Peripheral Functionalities around a Pyridine Core on Molecular Arrangement: Potential Hole Transport Materials

作者：Krishan Kumar, Mangey Ram Nagar, Anirban Karmakar, Fengrong Chen, Jwo‐Huei Jou, Subrata Ghosh, Sunil Kumar, Subrata Banik · 发表于：Crystal Growth & Design · 年份：2023 · DOI：10.1021/acs.cgd.3c00911 · 被引用次数：7 · 研究领域：Organic Light-Emitting Diodes Research、Organic Electronics and Photovoltaics、Molecular Junctions and Nanostructures

Given that optoelectronic devices are the solid-state application of associated materials and considering that rationally functionalized pyridines are emerging as promising hole transport materials (HTMs) for optoelectronic devices, the present work reports in-depth insights through detailed experimental and theoretical studies on how the peripheral substituents of a pyridine core may affect various properties of HTMs for organic light-emitting diodes. In this regard, four compounds, P 3 C 0 Py, P 2 C 1 Py, P 1 C 2 Py, and P 0 C 3 Py, have been synthesized for the current study where the number of peripheral carbazole units was systematically varied to study the change in molecular arrangements in the solid state. Such strategic functionalization led to a reduction in hole reorganization energy, which may further lead to significant enhancement in hole transport properties. The high triplet energy of these molecules might reduce the exciton quenching at the interface of the hole injection layer (HIL) and the emissive layer (EML). The theortically calculated charge transfer excited singlet state at a higher oscillator strength indicated the charge transfer characteristics of these molecules. Similarly, the theortical low hole and exciton binding energies indicated that the current materials may show high hole transportability. The single crystal analysis revealed how molecular arrangement varies from zig-zag to wavelike patterns with a change in the number of peripheral carbaz...