Jiaxin Gao

The development of high-efficiency organic solar cells (OSCs) processed from non-halogenated solvents is crucially important for their scale-up industry production. However, owing to the difficulty of regulating molecular aggregation, there is a huge efficiency gap between non-halogenated and halogenated solvent processed OSCs. Herein, we fabricate o-xylene processed OSCs with approaching 20 % efficiency by incorporating a trimeric guest acceptor named Tri-V into the PM6:L8-BO-X host blend. The incorporation of Tri-V effectively restricts the excessive aggregation of L8-BO-X, regulates the molecular packing and optimizes the phase-separation morphology, which leads to mitigated trap density states, reduced energy loss and suppressed charge recombination. Consequently, the PM6:L8-BO-X:Tri-V-based device achieves an efficiency of 19.82 %, representing the highest efficiency for non-halogenated solvent-processed OSCs reported to date. Noticeably, with the addition of Tri-V, the ternary device shows an improved photostability than binary PM6:L8-BO-X-based device, and maintains 80 % of the initial efficiency after continuous illumination for 1380 h. This work provides a feasible approach for fabricating high-efficiency, stable, eco-friendly OSCs, and sheds new light on the large-scale industrial production of OSCs.

Although proton conductors derived from metal–organic frameworks (MOFs) are highly anticipated for various applications including solid‐state electrolytes, H 2 sensors, and ammonia synthesis, they are facing serious challenges such as poor water stability, fastidious working conditions, and low proton conductivity. Herein, we report two lanthanide–oxalate MOFs that are highly water stable, with so far the highest room‐temperature proton conductivity (3.42 × 10 −3 S cm −1 ) under 100% relative humidity (RH) among lanthanide‐based MOFs and, most importantly, luminescent. Moreover, the simultaneous response of both the proton conductivity and luminescence intensity to RH allows the linkage of proton conductivity with luminescence intensity. This way, the electric signal of proton conductivity variation versus RH will be readily translated to optical signal of luminescence intensity, which can be directly visualized by the naked eye. If proper lanthanide ions or even transition‐metal ions are used, the working wavelengths of luminescence emissions can be further extended from visible to near infrared light for even wider‐range applications.

Abstract Although all‐polymer solar cells (all‐PSCs) show great commercialization prospects, their power conversion efficiencies (PCEs) still fall behind their small molecule acceptor‐based counterparts. In all‐polymer blends, the optimized morphology and high molecular ordering are difficult to achieve since there is troublesome competition between the crystallinity of the polymer donor and acceptor during the film‐formation process. Therefore, it is challenging to improve the performance of all‐PSCs. Herein, a ternary strategy is adopted to modulate the morphology and the molecular crystallinity of an all‐polymer blend, in which PM6:PY‐82 is selected as the host blend and PY‐DT is employed as a guest component. Benefiting from the favorable miscibility of the two acceptors and the higher regularity of PY‐DT, the ternary matrix features a well‐defined fibrillar morphology and improved molecular ordering. Consequently, the champion PM6:PY‐82:PY‐DT device produces a record‐high PCE of 18.03%, with simultaneously improved open‐circuit voltage, short‐circuit current and fill factor in comparison with the binary devices. High‐performance large‐area (1 cm 2 ) and thick‐film (300 nm) all‐PSCs are also successfully fabricated with PCEs of 16.35% and 15.70%, respectively.Moreover, 16.5 cm 2 organic solar module affords an encouraging PCE of 13.84% when using the non‐halogenated solvent , showing the great potential of “Lab‐to‐Fab” transition of all‐PSCs.