The morphological analysis of bulk heterojunction (BHJ) active layer stands as a critical imperative for advancing the performance of future organic solar cells. Conventional characterization tools employed for morphological investigation often require substantial resources, both in cost and physical space, thereby imposing restraints on research endeavors in this domain. Here, we extend the application of charge carrier transport characterization beyond conventional mobility assessments, utilizing it as a table-top method for preliminary morphological screening in organic thin films. The investigation focuses on several high-performance BHJ systems that utilize typical “Y” non-fullerene acceptors. It involves in-depth transport studies, including temperature- and field-dependent transport characterizations. The resulting transport data are analyzed in detail using the Gaussian disorder model to extract key transport parameters, specifically the high-temperature limited mobility (μ∞) and positional disorder (∑). Integrating these transport parameters with morphological insights obtained through various characterization tools—including x-ray scattering, sensitive spectroscopy, and quantum chemistry simulation—provides a deep understanding of the intricate interplay between charge transport properties and morphological characteristics. The results reveal explicit relationships, associating μ∞ with the degree of molecular stacking in BHJs and ∑ with the structural disorder in molecule skeleton. Our findings point to the promising potential of utilizing a simple transport characterization technique for the early stage evaluation of thin film packing and geometric properties of organic materials.

中文翻译：

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与温度相关的电荷传输测量揭示了非富勒烯有机太阳能电池的形态学见解


体异质结 （BHJ） 活性层的形态分析是提高未来有机太阳能电池性能的关键必要条件。用于形态学研究的传统表征工具通常需要大量资源，包括成本和物理空间，从而限制了该领域的研究工作。在这里，我们将电荷载流子传输表征的应用扩展到传统的迁移率评估之外，将其用作有机薄膜初步形态筛选的桌面方法。该研究的重点是几种使用典型“Y”非富勒烯受体的高性能 BHJ 系统。它涉及深入的输运研究，包括温度和场依赖性的输运表征。使用高斯无序模型详细分析所得的传输数据，以提取关键的传输参数，特别是高温有限迁移率 （μ∞） 和位置无序 （∑）。将这些输运参数与通过各种表征工具（包括 X 射线散射、灵敏光谱和量子化学模拟）获得的形态学见解相结合，可以深入了解电荷传输特性和形态特性之间错综复杂的相互作用。结果揭示了明确的关系，将 μ∞ 与 BHJ 中的分子堆叠程度相关联，∑与分子骨架中的结构无序相关联。我们的研究结果表明，利用简单的传输表征技术对有机材料的薄膜堆积和几何特性进行早期评估具有广阔的潜力。