Dingqin Hu

Developing molecular materials with high intrinsic n ‐type electrical conductivity ( σ ) independent of extrinsic doping remains a formidable challenge in organic electronics. Herein, we report a novel acceptor–acceptor type open‐shell conjugated polymer (OSCP), PBBT‐gDPP, featuring a proquinoidal benzobis(1,2,5‐thiadiazole) (BBT)‐based backbone and polar oligo(ethylene glycol) side chains. In‐depth spectroscopic, electrochemical, and magnetic characterizations uncover that this acceptor–acceptor architecture, benefiting from its planar backbone and multiple proquinoidal units, yields an ultra‐narrow bandgap ( E _g < 0.6 eV), an open‐shell triplet ground state ( S = 1), and significant diradicaloid character. These features, complemented by polar side chains that modulate the local dielectric environment to assist in polaron transport, result in a high intrinsic σ of 9.21 S cm ⁻¹ with substantial ambient stability and a power factor of 6.49 µW m ⁻¹ K ⁻² when PBBT‐gDPP is applied as an n ‐type single‐component organic thermoelectric material. The conductivity surpasses those of previously reported undoped conjugated materials. Notably, the near‐amorphous morphology, characterized by a high paracrystalline disorder parameter of ∼23%, imparts exceptional mechanical robustness, retaining 80% of its initial σ s after 3000 bending cycles. This work underscores the significant potential of polar high‐spin OSCPs for next‐generation, dopant‐free, and flexible organic electronics.

Developing molecular materials with high intrinsic n ‐type electrical conductivity ( σ ) independent of extrinsic doping remains a formidable challenge in organic electronics. Herein, we report a novel acceptor–acceptor type open‐shell conjugated polymer (OSCP), PBBT‐gDPP, featuring a proquinoidal benzobis(1,2,5‐thiadiazole) (BBT)‐based backbone and polar oligo(ethylene glycol) side chains. In‐depth spectroscopic, electrochemical, and magnetic characterizations uncover that this acceptor–acceptor architecture, benefiting from its planar backbone and multiple proquinoidal units, yields an ultra‐narrow bandgap ( E _g < 0.6 eV), an open‐shell triplet ground state ( S = 1), and significant diradicaloid character. These features, complemented by polar side chains that modulate the local dielectric environment to assist in polaron transport, result in a high intrinsic σ of 9.21 S cm ⁻¹ with substantial ambient stability and a power factor of 6.49 µW m ⁻¹ K ⁻² when PBBT‐gDPP is applied as an n ‐type single‐component organic thermoelectric material. The conductivity surpasses those of previously reported undoped conjugated materials. Notably, the near‐amorphous morphology, characterized by a high paracrystalline disorder parameter of ∼23%, imparts exceptional mechanical robustness, retaining 80% of its initial σ s after 3000 bending cycles. This work underscores the significant potential of polar high‐spin OSCPs for next‐generation, dopant‐free, and flexible organic electronics.

Organic solar cells are among the most advanced thin‐film photovoltaic technologies due to their lightweight, thin, and flexible characteristics. However, an inherent trade‐off between open‐circuit voltage ( V _OC ) and short‐circuit current density ( J _SC ) exists, fundamentally stemming from the balance between charge generation and recombination. To address this challenge, we developed a two‐dimensional extension molecule based on the A‐D‐A′‐D‐A non‐fullerene acceptor (NFA) framework by replacing the central core with anthracene and introducing halogen‐free end groups, yielding a novel molecule named QxAt. This molecule combines high crystallinity with a complementary absorption spectrum to commonly used NFAs. When incorporated as a voltage‐current balancer into the PM6:BTP‐eC9 system, the active layer morphology was largely preserved, while molecular packing was modestly optimized, contributing to more efficient exciton dissociation and charge collection, improved hole and electron mobilities, and effective suppression of charge recombination, ultimately enabling a moderate improvement in J _SC . More importantly, QxAt significantly increased the electroluminescence quantum efficiency, effectively suppressing non‐radiative recombination and reducing energy loss, which in turn elevated V _OC . Consequently, the PCE was markedly improved from 18.9% to 20.1%, achieving a synergistic optimization of both V _OC and J _SC . This work provides a molecular design strategy to mitigate the voltage‐current trade‐off for high‐efficiency organic photovoltaics.

Molecular aggregation behavior of non‐fullerene acceptors (NFAs) plays a pivotal role in the photovoltaic performance of organic solar cells (OSCs). In Y‐series NFAs, excessive H‐like core contacts may increase packing disorder, while terminal group‐mediated J‐like interactions favor electronic coupling, luminescence, and reduced nonradiative loss. Controlling the H/J aggregation balance therefore remains a key challenge. Herein, three novel NFAs—C8C8, C8‐7R, and C8EH—featuring identical conjugated backbones but systematically varied inner alkyl chains were designed to finely modulate aggregation states. Theoretical calculations and single‐crystal analysis show that increased inner‐chain steric hindrance suppresses core‐involved contacts (H‐aggregation) while favoring terminal group‐mediated (J‐aggregation) interactions. Accordingly, C8EH exhibits the strongest J‐preferred packing tendency and enhanced molecular ordering, supported by compact terminal contacts, redshifted absorption, faster aggregation, and refined fibrillar morphology. When fabricated with the donor D18, C8EH‐based OSC devices delivered an outstanding power conversion efficiency (PCE) of 20.73%, representing one of the highest values reported for additive‐ and annealing‐free OSCs with higher current and reduced energy loss. This work demonstrates that inner‐chain steric modulation can promote J‐aggregated packing and ordered molecular organization, providing an effective strategy for high‐performance NFAs and process‐simplified OSCs.

The co-adsorption of Me-4PACz with 4MBA molecule on NiO _x substrate has substantially improved NiO _x /SAM/perovskite interfacial characteristics and optimized perovskite crystallization leading to a high efficiency of 27.05% for resultant solar cells.

The rational design of efficient self‐assembled interlayers (SAIs) is pivotal for overcoming the efficiency bottleneck in organic solar cells (OSCs), in which substantial nonradiative energy losses limit further performance improvements. In this study, guided by theoretical calculations, we report a series of new SAI materials ( BT‐nBZCz ; n = 2, 3, and 4) based on a benzocarbazole core functionalized with a benzo[b]thiophene (BT) unit, and systematically investigate their impact on nonradiative losses and OSC performance. Notably, binary OSCs incorporating BT‐4BZCz achieve a significantly higher power conversion efficiency (PCE) of 20.46% compared to 18.08% for BT‐free SAIs. Combined theoretical and experimental analyses reveal that BT functionalization improves energy level alignment, enhances dipole moment, and optimizes molecular packing, crystallization kinetics, and fibrillar network formation relative to BT‐free SAIs. These improvements promote more efficient exciton dissociation, reduce charge recombination, and in particular, suppress nonradiative energy losses (0.284 vs. 0.217 eV) in the corresponding OSCs. Furthermore, BT‐4BZCz exhibits excellent universality, maintaining high performance across various binary photoactive blends. This work presents a viable molecular engineering strategy for SAIs to suppress nonradiative losses and advance the development of high‐performance OSCs.

Scalability and automation are critical for advancing organic solar cells (OSCs) toward high-throughput production, yet both remain notable challenges. Here, we report a simple yet effective strategy using Tz6T as a multifunctional additive to regulate ink-state preaggregation to address both concerns. Tz6T interacts with both donor and acceptor molecules in ink, enabling improved and more ordered preaggregation. This facilitates uniform film formation and significantly reduces bimolecular recombination, enables 16.4% efficiency large-area green solvent–processed OSC modules (19.3 cm ² ), ranking it among the best reported values to date. Furthermore, the preagggregated ink mitigates the morphology drift caused by time delays in preprogrammed robotic fabrication, yielding device efficiency exceeding 16%, highlighting strong potential for high-throughput production. Beyond efficiency, Tz6T also enhances long-term stability and exhibits compatibility across diverse material systems, underscoring its broad applicability. This work offers a promising pathway for accelerating the translation toward sustainable, scalable, and automated fabricable high-performance and stable OSCs, paving the way for their industrialization.

Incorporating BzMIMBF ₄ layer into Me-4PACz (SAM) boosts the perovskite/HTL interface via strong π-conjugated heterojunctions, passivating perovskite defects and thus resulting in stable PSCs with a high PCE of up to 26.45%.

The incorporation of bowl-shaped corannulene as a solid additive in the active layer enhances organic solar cell efficiency to 20.52%, alongside remarkable thermal stability with a T₈₅ lifespan of 2007 h.

Ternary organic solar cells incorporating a bithiophene imide-based polymer donor in a dual-donor system achieve an outstanding efficiency of 20.52% and excellent thermal stability, retaining over 92.2% performance after 1008 h of heating.