Charge transfer (CT) between donors and acceptors following photoexcitation of organic photovoltaics (OPVs) gives rise to bound electron–hole pairs across the donor–acceptor interface, known as CT states. While these states are essential to charge separation, they are also a source of energy loss. As a result of reduced overlap between electron and hole wavefunctions, CT states are influenced by details of the film morphology and molecular structure. Here, we describe several important strategies for tuning the energy level and dynamics of the CT state and approaches that can enhance their dissociation efficiency into free charges. Furthermore, we provide an overview of recent physical insights into the key parameters that significantly reduce the Frenkel-to-CT energy offset and recombination energy losses while preserving a high charge-generation yield. Our analysis leads to critical morphological and molecular design strategies for achieving efficient, low-energy-loss OPVs.

有机光伏（OPV）的光激发后，供体和受体之间的电荷转移（CT）导致跨供体-受体界面的束缚电子-空穴对，称为CT状态。虽然这些状态对于电荷分离必不可少，但它们也是能量损失的来源。由于电子和空穴波函数之间的重叠减少，CT状态受到薄膜形态和分子结构细节的影响。在这里，我们描述了几种重要的策略，它们可以用来调节CT状态的能级和动态，以及可以增强将它们分解为自由电荷的效率的方法。此外，我们提供了对关键参数的最新物理见解的概述，这些关键参数可显着减少Frenkel到CT的能量偏移和复合能量的损失，同时保持高的电荷产生率。我们的分析提出了关键的形态和分子设计策略，以实现高效，低能耗的OPV。