近日，美国落基山国家实验室Obadiah G. Reid团队报道了在固体有机供体-受体体系中，光致电子转移距离由驱动力控制。2026年3月25日出版的《自然-化学》杂志发表了这项成果。

理解有机太阳能电池中短程电子转移如何产生光电流，以及需要何种光化学驱动力才能使效率最大化，一直是一个极其困难的问题。

研究组揭示了这些问题的内在关联：驱动力控制着平均电荷转移距离，在最优情况下跳过了最短程的态。通过使用光诱导吸收检测磁共振技术，他们测量了稀溶液给体-受体共混物中平均电荷分离距离随驱动力的变化，并将其与时间分辨微波电导率测量的自由电荷产率进行了比较。

结果发现，最大的驱动力表现出最短的电荷分离距离，这解释了其自由载流子生成受到抑制的现象。这些结果支持长程电子转移模型，在该模型中，驱动力控制着电子-空穴对的初始离域程度。高效电荷分离（以及最小电压损失）所需的最小驱动力，最终由材料的介电常数决定。

附：英文原文

Title: Photoinduced electron-transfer distance is controlled by the driving force in solid-state organic donor–acceptor systems

Author: Romanetz, Leo, Gish, Melissa K., Aubry, Taylor J., Rumbles, Garry, Reid, Obadiah G.

Issue&Volume: 2026-03-25

Abstract: Understanding how short-range electron transfer generates photocurrent in organic solar cells and what photochemical driving force is needed to maximize efficiencies has been an immensely difficult problem. Here we show how these questions are intertwined: the driving force controls the average charge-transfer distance, skipping the shortest-range states in the optimal case. Using photoinduced absorption-detected magnetic resonance, we measure average charge-separation distances in dilute donor–acceptor blends as a function of driving force, and compare these with free charge yields measured by time-resolved microwave conductivity. We find that the largest driving forces show the shortest charge-separation distances, explaining their suppressed free-carrier generation. These results support a long-range electron-transfer model, wherein the driving force controls the initial delocalization of the electron–hole pair. The minimum driving force required for efficient charge separation (and minimal voltage losses) is ultimately set by the dielectric constant of the material.

DOI: 10.1038/s41557-026-02089-7

Source: https://www.nature.com/articles/s41557-026-02089-7