The preparation of high‐quality perovskite films is important for achieving high‐performance perovskite solar cells (PSCs). The effective balance between solvent and antisolvent is an essential factor for regulating high‐quality perovskite film during the spin‐coating and thermal‐annealing steps. In this work, a greener, nonhalogenated, nontoxic bifunctional (anti)solvent, methyl benzoate (MB), is developed not only as an antisolvent to rapidly generate crystal seeds at the perovskite spin‐coating step, but also as a digestive‐ripening solvent for the perovskite precursors, which can prevent the loss of organic components during the thermal‐annealing stage and effectively suppress the formation of miscellaneous lead halide phases. As a result, this novel bifunctional (anti)solvent is employed in planar n–i–p PSCs for engineering high‐quality perovskite layers and thus achieving a power conversion efficiency up to 22.37% with negligible hysteresis and >1300 h stability. Moreover, due to the high boiling point and low‐volatility characteristic of MB, high‐performance PSCs are achieved reproducibly at different operating temperatures (22–34 °C). Therefore, this developed bifunctional solvent system can provide a promising platform toward globally upscaling and commercializing PSCs in all seasons and regions.

Rapid processing technologies of perovskite solar cells (PSCs) offer an exciting approach to raise the rate of production. Herein, a rapid microwave‐annealing process (MAP) is reported to replace the traditional hotplate annealing process (HAP) and the processing period of perovskite is reduced to less than 1 min. Benefiting from the penetrability and simultaneity of microwave irradiation, the MAP method can effectively eliminate miscellaneous phases and thus achieve >1 µm large‐size crystal grains in perovskite films. These MAP treated perovskite films exhibit pure crystalline phase, long charge‐carrier lifetime, and low defect density, which can substantially improve the PSC efficiency without requiring an additional enhancer/passivation layer. The inverted planar PSCs present enhanced power conversion efficiency from 18.33% (HAP) to 21.59% (MAP) and good stability of >1000 h lifetime without encapsulation under ambient conditions. In addition, MAP can be applied to a large‐size (10 cm × 10 cm) perovskite film fabrication as well as a broader tolerance in environmental temperature and precursor concentration, making it a reliable method for repeatably practical fabrication of perovskite photovoltaics.

Halide perovskites with low-dimensionalities (2D or quasi-2D) have demonstrated outstanding stabilities compared to their 3D counterparts. Nevertheless, poor charge-transporting abilities of organic components in 2D perovskites lead to relatively low power conversion efficiency (PCE) and thus limit their applications in photovoltaics. Here, we report a novel hole-transporting low-dimensional (HT2D) perovskite, which can form a hole-transporting channel on the top surface of 3D perovskite due to self-assembly effects of metal halide frameworks. This HT2D perovskite can significantly reduce interface trap densities and enhance hole-extracting abilities of a heterojunction region between the 3D perovskite and hole-transporting layer. Furthermore, the posttreatment by HT2D can also reduce the crystal defects of perovskite and improve film morphology. As a result, perovskite solar cells (PSCs) can effectively suppress nonradiative recombination, leading to an increasement on photovoltage to >1.20 V and thus achieving >20% power conversion efficiency and >500 h continuous illumination stability. This work provides a pathway to overcome charge-transporting limitations in low-dimensional perovskites and delivers significant enhancements on performance of PSCs.

Plant volatiles can act as chemical signals that influence the behavior and distribution of insects. Although considerable information has been acquired on the effects of plant volatiles emitted from plants on herbivorous insects and their natural enemies, practical implementation of this knowledge is still lacking. We investigated 3 aromatic plant species, French marigold, Tagetes patula L. (Asteraceae), ageratum, Ageratum houstonianum Mill. (Asteraceae), and catnip, Nepeta cataria L. (Lamiaceae), to test their effectiveness in repelling or attracting spirea aphid, Aphis citricola van der Goot (Hemiptera: Aphididae), and its natural enemy, the multicolored Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), in the field and the laboratory. We found that intercropping apple trees Malus spp. (Rosaceae) with aromatic plants in an orchard significantly reduced the number of A. citricola aphids present, but had the opposite effect on H. axyridis. In addition, the association between H. axyridis and A. citricola numbers was strengthened when the intercropping included French marigold. Using an H-tube olfactometer, we found that A. citricola was repelled by French marigold and catnip, whereas H. axyridis was attracted most by French marigold. Volatile analysis revealed that the sesquiterpenes Dlimonene and terpinolene and the alcohol 2-ethyl-1-hexanol were the most abundant volatile compounds released by French marigold and catnip. Harmonia axyridis was significantly attracted by 12.5 μL/L D-limonene, 50 μL/L terpinolene, and 25 μL/L of a 1:1 mixture of the 2 compounds, but was repelled by higher concentrations of D-limonene. The results suggest that aromatic plants increase the resistance of apple trees to A. citricola both directly, by reducing the population of A. citricola through chemical repulsion, and indirectly, by increasing the H. axyridis population through chemical attraction.

Three conjugated polymers based on different linkage sites of carbazole repeat units, 3,6-PCzTPA, 2,7-PCzTPA, and 3,6-2,7-PCzTPA, were obtained through judicious molecular engineering. We observed that structure differences between 2,7-and 3,6-carbazole linkage sites could significantly influence intra-and intermolecular architectures and electronic states of materials. Herein, 3,6-PCzTPA and 3,6-2,7-PCzTPA with 3,6-carbazole units exhibited higher hole mobilities owing to the formation of radical cations, compared to 2,7-PCzTPA with 2,7-carbazole units. As a result, by using 3,6-2,7-PCzTPA as the hole-transporting material, perovskite solar cells with the p−i−n structure demonstrated the highest power conversion efficiency up to 18.4%. The outstanding device performance originated from compositive values of open-circuit voltage and fill factor, which were attributed to the suitable energy level as well as a high hole mobility of 3,6-2,7-PCzTPA. Moreover, its straightforward synthesis strategy, fine film-formation ability, and nondopant requirement indicated 3,6-2,7-PCzTPA as an ideal hole-transporting material for perovskite solar cells.