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Introducing a third component into organic bulk heterojunction solar cells has become an effective strategy to improve photovoltaic performance. Meanwhile, the rapid development of non-fullerene acceptors (NFAs) has pushed the power conversion efficiency (PCE) of organic solar cells (OSCs) to a higher standard. Herein, a series of fullerene-free ternary solar cells are fabricated based on a wide bandgap acceptor, IDTT-M, together with a wide bandgap donor polymer PM6 and a narrow bandgap NFA Y6. Insights from the morphological and electronic characterizations reveal that IDTT-M has been incorporated into Y6 domains without disrupting its molecular packing and sacrificing its electron mobility and work synergistically with Y6 to regulate the packing pattern of PM6, leading to enhanced hole mobility and suppressed recombination. IDTT-M further functions as an energy-level mediator that increases open-circuit voltage (VOC) in ternary devices. In addition, efficient Förster resonance energy transfer (FRET) between IDTT-M and Y6 provides a non-radiative pathway for facilitating exciton dissociation and charge collection. As a result, the optimized ternary device features a significantly improved PCE up to 16.63% with simultaneously enhanced short-circuit current (JSC), VOC, and fill factor (FF).

[Objective] Northeast China, with its unique resources advantages, provides one-third of China’s commodity grain, making it a crucial part of national food security. Analyzing the spatial distribution, spatiotemporal evolution, and driving forces of grain crop cover types and cropping patterns in Northeast China is crucial for preserving the region’s “black soil granary”. [Methods] Based on Google Earth Engine (GEE), this study integrated existing crop cover type product from 2017 to 2019 with remote sensing extraction results of major grain crops from 2019 to 2021, analyzed the spatiotemporal change characteristics of grain crop planting types and cropping patterns, then revealed the driving forces by using geodetector. [Results] (1) Using phenological information, a multi-feature random forest classification method was employed to effectively extract three major grain crops: maize, soybean, and rice. In 2019, a high Kappa coefficient of 0.908 was achieved, indicating high classification accuracy and consistency in terms of area. (2) In the past five years, the shifting of grain crops from soybeans to maize has been the dominant trend in Northeast China. The shift types include soybean to maize to maize, soybean to soybean to maize, and maize to maize to soybean, accounting for 29.4%, 24.9%, and 19.1% of the total transition area, respectively. The cropping patterns of grain crops in Northeast China exhibit high spatial heterogeneity, with the maize continuous cropping pattern, rice continuous cropping pattern, and soybean-maize continuous-preference rotation pattern accounted for 46.2 %, 23.5 %, and 13.2 % of the total cropping patterns area, respectively. (3) The spatiotemporal dynamics of cropping patterns was significantly driven by natural and anthropogenic factors. Elevation, topographic wetness index, slope, rice price fluctuation, and soybean price fluctuation were important single factors that explain the spatiotemporal changes of cropping patterns. The interactive explanatory power of elevation, active accumulated temperature slope, and economic policy factors was high, and in descending order from elevation∩soybean subsidy variation, elevation∩active accumulated temperature slope, elevation∩fertilization cost variation, elevation∩rice subsidy variation, to elevation∩maize price variation. [Conclusion] During the period from 2017 to 2021, there was a notable shift in the major grain crop cover types in Northeast China, characterized by a transition from soybean to maize, while rice cultivation remained consistent. The spatial distribution of different cropping patterns was influenced by a combination of factors including topography, economy, and policy.