Articles
Publication Date: 2026
pp. 77-93
Redox-flow batteries (RFBs) show bright prospects as candidates for large-scale energy storage involving grid-scale electricity construction with flexible intermittent electricity and simplified manufacturing processes. The RFBs are propounded as worthy for industrial requests owing to their flexible serviceability, modular design, and good scalability. The redox-active species has the most vital task in the RFBs and can control the system capacity and energy density via solubility and the redox potential. The energy density is controlled by the solubility of the electroactive materials, cell voltage, and the number of electrons transferred. Molecular engineering has a crucial influence on the solubility of organic redox in electrolytes and justifies the redox potential of organic compounds through the attachment of polar/nonpolar moieties and electron-withdrawing/donating groups adjacent to the redox center. The cost issue and tunable structure of organic redox-active materials have a critical impact on the development of organic and aqueous RFBs. Herein, we focus on molecular engineering strategies related to the enhancement of the solubility and stability of organic redoxmers as posolytes and negolytes in both organic and aqueous RFBs. This chapter is focused on famous categories of active materials, including viologen, quinone, anthraquinone, quinoxaline, and phenazine in aqueous and nonaqueous configuration flow batteries. © 2026 selection and editorial matter, Ram K. Gupta; individual chapters, the contributors.
Publication Date: 2025
ACS Nano (19360851)19(7)pp. 6784-6794
Organic hole-transporting materials (HTMs) with high hole mobility and a defect passivating ability are critical for improving the performance and stability of perovskite optoelectronics, including perovskite quantum dot light-emitting diodes (Pe-QLEDs) and perovskite solar cells. In this study, we designed two small-molecule HTMs, termed X13 and X15, incorporating the methylthio group (SMe) as defect-passivating sites to enhance the interaction between HTMs and the perovskite layer for Pe-QLED applications. Our study highlights that X15, featuring SMe groups at the para-position of the carbazole unit, demonstrates a strong interaction and superior passivation effects with perovskite quantum dots. Consequently, Pe-QLEDs (0.09 cm2) incorporating X15 as the HTM achieve a maximum external quantum efficiency (EQE) of 22.89%. Moreover, employing X15 in large-area Pe-QLEDs (1 cm2) yields an EQE of 21.10% with uniform light emission, surpassing the PTAA-based devices (EQE ∼ 15.03%). Our finding provides crucial insights into the molecular design of defect-passivating small-molecule HTMs for perovskite light-emitting diodes and related optoelectronic devices. © 2025 American Chemical Society.
Publication Date: 2025
Nanomaterials (20794991)15(13)
In recent years, inverted perovskite solar cells (PSCs) have garnered widespread attention due to their high compatibility, excellent stability, and potential for low-temperature manufacturing. However, most of the current research has primarily focused on the surface passivation of perovskite. In contrast, the buried interface significantly influences the crystal growth quality of perovskite, but it is difficult to effectively control, leading to relatively slow research progress. To address the issue of poor interfacial contact between the hole transport-layer nickel oxide (NiOX) and the perovskite, we introduced a conjugated self-assembled monolayer (SAM), 4,4′-[(4-(3,6-dimethoxy-9H-carbazole)triphenylamine)]diphenylacetic acid (XS21), which features triphenylamine dicarboxylate groups. For comparison, we also employed the widely studied phosphonic acid-based SAM, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl] phosphonic acid (MeO-2PACz). A systematic investigation was carried out to evaluate the influence of these SAMs on the performance and stability of inverted PSCs. The results show that both XS21 and MeO-2PACz significantly enhanced the crystallinity of the perovskite layer, reduced defect densities, and suppressed non-radiative recombination. These improvements led to more efficient hole extraction and transport at the buried interface. Consequently, inverted PSCs incorporating XS21 and MeO-2PACz achieved impressive power-conversion efficiencies (PCEs) of 21.43% and 22.43%, respectively, along with marked enhancements in operational stability. © 2025 by the authors.
