Institute of Optoelectronic Display, National & Local United Engineering Lab of Flat Panel Display Technology, Fuzhou University, Fuzhou, 350002, China.
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, 350100, China.
Nat Commun. 2023 Mar 22;14(1):1579. doi: 10.1038/s41467-023-37174-9.
Limited by the inherent energy loss (E) in carrier transport process, the device efficiency of organic solar cells shows inferior to traditional inorganic photovoltaic devices. Generally, molecular design, morphology optimization and interfacial engineering are usually required to alleviate E. Here, vertical field-effect organic photovoltaic (VFEOPV) by integrating an bulk-heterojunction (BHJ) organic photovoltaic (OPV) with vertical field effect transistor (VFET) is invented, in which VFET generates a large, uneven, internal electric field, eliminating the requirement for driving force to dissociate excitons and prevents non-radiative recombination in OPV. In this way, the performance of solar cell can be well controlled by the gate voltage of VFET and the E of VFEOPVs based on J71: ITIC system is dramatically reduced below 0.2 eV, significantly improving power conversion efficiency (PCE) from 10% to 18% under gate voltage of 0.9 V, which only causes negligible additional power consumption (~10mJ/cm). Besides, the device also exhibits multi-functionality including transistor and phototransistors with excellent photodector performance. This work provides a new and general strategy to improve the OPV performance which is compatible with present optimization methods, and can be applied to improve PCE of other types of solar cells such as Perovskite and inorganic solar cells.
受载流子输运过程中固有能量损失 (E) 的限制，有机太阳能电池的器件效率不如传统的无机光伏器件。通常需要通过分子设计、形貌优化和界面工程来缓解 E。在这里，通过将体异质结 (BHJ) 有机光伏 (OPV) 与垂直场效应晶体管 (VFET) 集成，发明了垂直场效应有机光伏 (VFEOPV)，其中 VFET 产生大、不均匀的内部电场，无需驱动力即可离解激子，并防止 OPV 中的非辐射复合。通过这种方式，可以通过 VFET 的栅极电压很好地控制太阳能电池的性能，并且基于 J71: ITIC 系统的 VFEOPV 的 E 显著降低到 0.2 eV 以下，在 0.9 V 的栅极电压下，功率转换效率 (PCE) 从 10%显著提高到 18%，而仅导致可忽略的额外功耗 (~10mJ/cm)。此外，该器件还具有晶体管和光电晶体管等多种功能，具有出色的光电探测器性能。这项工作为改善 OPV 性能提供了一种新的通用策略，与现有优化方法兼容，并且可以应用于提高其他类型的太阳能电池（如钙钛矿和无机太阳能电池）的 PCE。
