Manjun Xiao

Although organic solar cells (OSCs) have made significant progress in photovoltaic performance, their practical applications still face challenges, such as the complex material synthesis and involvement of Stille coupling reaction with organotin reagents of fused‐ring electron acceptors, and using halogenated toxic solvents in device fabrication. Here, we develop two non‐fully‐fused dimeric acceptors (named dNA‐C6 and dNA‐C12) with varying alkyl linker lengths using organotin‐free C‐H activation approach, which present the advantages of environmental friendliness and easy synthesis. When introducing dNA‐C6 and dNA‐C12 into PM6:BTP‐eC9 system, these OSCs achieve higher power conversion efficiencies (PCEs) of 19.07% and 18.74%, respectively, compared to their parental monomer based device (18.44%), while the dNA‐C6 based OSC obtains both superior PCE and device stability. Moreover, dNA‐C6 is also introduced into D18:BTP‐eC9 host to verify its universality in boosting photovoltaic performance, and the relevant device processed with halogen‐free o ‐xylene offers a further improved PCE of 20.17%, ranking among the highest values in the reported non‐fully‐conjugated dimeric acceptors and halogen‐free solvent processed OSCs. This work develops organotin‐free synthesized non‐fully‐fused dimeric acceptors by integrating eco‐friendly chemistry for preparing green solvent processed OSCs with high PCE and device stability.

Giant‐molecule acceptors (GMAs) have been proven to improve power‐conversion‐efficiency (PCE) and stability of organic solar cells (OSCs), while most high‐performance GMAs only attach two monomers and primarily exhibit the properties of their monomer precursors. Herein, we develop four trimeric GMAs (named 3Y‐site, including wing‐sites‐linked 3Y‐Wing, end‐sites‐linked 3Y‐End, hybrid wing/end‐sites‐linked 3Y‐EWE and 3Y‐WEW) with the same alkylated linker but different linking sites to fine‐tune molecular optoelectronic properties. Among them, 3Y‐Wing with a superior planarity and extensibility possesses broadened absorption, better crystallinity, superior packing, and higher glass transition temperature, resulting in an optimized phase separation. The optimized devices with binary PM6:3Y‐Wing and ternary PM6:L8‐BO:3Y‐Wing achieve both champion PCEs of 15.0% and 19.1%, respectively, along with enhanced light, thermal, and storage stabilities, outperforming devices based on all other 3Y‐site counterparts. In the classic D18:L8‐BO host system, the effectiveness of 3Y‐Wing in boosting PCE is further validated, and the resulted ternary devices deliver an excellent PCE of 20.23%, setting an efficiency record among the reported trimeric GMAs. Moreover, the 3Y‐Wing based OSCs offer a better balance of high PCE and stability, further distinguishing them within 3Y‐site series. Our developed wing‐sites‐linked trimeric 3Y‐Wing is a promising candidate to achieve both high device efficiency and stability.

Giant‐molecule acceptors (GMAs) have been proven to improve power‐conversion‐efficiency (PCE) and stability of organic solar cells (OSCs), while most high‐performance GMAs only attach two monomers and primarily exhibit the properties of their monomer precursors. Herein, we develop four trimeric GMAs (named 3Y‐site, including wing‐sites‐linked 3Y‐Wing, end‐sites‐linked 3Y‐End, hybrid wing/end‐sites‐linked 3Y‐EWE and 3Y‐WEW) with the same alkylated linker but different linking sites to fine‐tune molecular optoelectronic properties. Among them, 3Y‐Wing with a superior planarity and extensibility possesses broadened absorption, better crystallinity, superior packing, and higher glass transition temperature, resulting in an optimized phase separation. The optimized devices with binary PM6:3Y‐Wing and ternary PM6:L8‐BO:3Y‐Wing achieve both champion PCEs of 15.0% and 19.1%, respectively, along with enhanced light, thermal, and storage stabilities, outperforming devices based on all other 3Y‐site counterparts. In the classic D18:L8‐BO host system, the effectiveness of 3Y‐Wing in boosting PCE is further validated, and the resulted ternary devices deliver an excellent PCE of 20.23%, setting an efficiency record among the reported trimeric GMAs. Moreover, the 3Y‐Wing based OSCs offer a better balance of high PCE and stability, further distinguishing them within 3Y‐site series. Our developed wing‐sites‐linked trimeric 3Y‐Wing is a promising candidate to achieve both high device efficiency and stability.

We developed two copolymers composed of BDD-Ph unit. PBF-C8 exhibited red-shifted absorption and stronger face-on stacking than PBF-EH, NF-PSCs based on PBF-C8 achieved a high PCE of 16.44%, significantly outperforming PBF-EH-based device (3.21%).

Organic solar cells (OSCs) based on non-fused ring electron acceptors (NFREAs) have shown significant potential for practical application owing to their easily tunable chemical structures and short synthesis routes. The merging of side-chain engineering and terminal-group halogenation has facilitated the optimization of NFREAs properties. Thus, in this study, we developed four NFREAs using a naphthalenediimide (NDI) unit with different alkyl side-chains (–C₆C₁₀ or –C₈C₁₂) as the building block and two different electron-withdrawing groups 2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene) malononitrile (IC) and chlorinated IC (IC-2Cl) as the terminal groups. These NFREAs were designated as NDI610-H, NDI610-Cl, NDI812-H, and NDI812-Cl, respectively. All four NFREAs exhibited similar optical bandgaps and molecular conformations. Under the synergistic effects of side-chain modification and terminal-group halogenation, the NFREAs-based active-layer morphologies were significantly different. The NDI610-Cl-based blended film demonstrated favorable phase-separation morphology, facilitating exciton dissociation and charge transport in the corresponding OSCs. Thus, the PM6:NDI610-Cl-based OSCs achieved a maximum power conversion efficiency (PCE) of 8.35%. Moreover, using D18 as the polymer donor further enhanced the device performance, with the D18:NDI610-Cl-based device yielding a higher PCE of 10.25% due to improved short-circuit current and fill factor. Our findings indicate that selecting an NDI unit as the building block and combining tailored alkyl side-chains with altered terminal groups are promising strategies for constructing highly efficient NFREAs.

Aqueous battery with nonflammable and instinctive safe properties has received great attention. However, issues related to Zn anode such as side reactions and rampant dendrite growth hinder the long‐term circulation of AZMBs. Herein, an ultrathin(35 nm) MoO ₃ coating is deposited on the Zn anode by means of vacuum vapor deposition for the first time. Due to the peculiar layer structure of MoO ₃ , insertion of Zn ²⁺ in Zn _x MoO ₃ acts as Zn ²⁺ ion conductor, which regulates Zn ²⁺ deposition in an ordered manner. Additionally, the MoO ₃ coating can also inhibit the hydrogen evolution and corrosion reactions at the interface. Therefore, both Zn//MoO ₃ @Cu asymmetric battery and Zn symmetric battery cells manage to deliver satisfactory electrochemical performances. The symmetric cell assembled with MoO ₃ @Zn shows a significant long cycle life of more than 1600 h at a current density of 2 mA cm ⁻² . Meanwhile, the MoO ₃ @Zn//Cu asymmetric cell exhibits an ultrahigh Zn deposition/stripping efficiency of 99.82% after a stable cycling of 650 h at 2 mA cm ⁻² . This study proposes a concept of “zincophile Zn ²⁺ conductor regulation” to dictate Zn electrodeposition and broadens novel design of vacuum evaporation for nano MoO ₃ modified Zn anodes.

Polymerized small molecular acceptors (PSMAs) as polymer acceptors demonstrate great potential in fabricating high-performance all-polymer solar cells (all-PSCs), but the available type of electron-deficient end-capping groups for polymerizable non-fullerene small molecular acceptors (NFSMAs) block is still few, limited by the commonly-used Stille polymerization method. Herein, we demonstrated novel PSMAs with an indacene-1,3,5,7-tetraone (ITO) motif as end-capping groups, namely PBDT-ITO and PBDTCl-ITO, and their application as acceptors for efficient all-PSCs. It was found that an electron-deficient ITO motif provides the relevant polymer with a stronger pull-push effect and larger conjugation length, resulting in lower-lying LUMO energy levels and decent electron mobility. After combining them with a classical polymer donor PM6 to fabricate binary all-PSCs, the PBDTCl-ITO-based device can deliver the best efficiency of 7.55% and a remarkable open-circuit voltage (V_OC) over 1 V. Relative to the PBDT-ITO-based counterpart, efficient hole/electron transfer, relatively higher and balanced charge transport property and proper morphology should be responsible for a better device performance. Furthermore, owing to the proper energy levels, complementary absorption and improved charge separation/transport, incorporating PBDTCl-ITO into an efficient PM6:PY-IT active layer can also promote V_OC and short-circuit current density (J_SC), thus leading to a ternary all-PSC with 16.08% efficiency. This work enriches the family of end-capping groups for designing efficient PSMAs, and further investigation on molecular backbone design, such as selection of core units and π-bridge units, would stimulate better all-PSC devices.