High-performance vertical field-effect organic photovoltaics

• Published in: Nature communications 2023-03, Vol.14 (1), p.1579-1579, Article 1579
• Main Authors: Wu, Xiaomin, Gao, Changsong, Chen, Qizhen, Yan, Yujie, Zhang, Guocheng, Guo, Tailiang, Chen, Huipeng
• Format: Article
• Language: English
• Subjects: 147/135; 147/3; 639/4077/4072/4062; 639/766/1130/2799; Carrier transport; Cytology; Design optimization; Efficiency; Electric fields; Electric potential; Energy conversion efficiency; Energy loss; Excitons; Field effect transistors; Heterojunctions; Humanities and Social Sciences; multidisciplinary; Perovskites; Phototransistors; Photovoltaic cells; Photovoltaics; Power consumption; Power management; Radiative recombination; Recombination; Science; Science (multidisciplinary); Semiconductor devices; Solar cells; Transistors; Transport processes; Voltage
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-37174-9

Limited by the inherent energy loss (E loss ) 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 loss . 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 loss 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 (~10 −4 mJ/cm 2 ). 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. The device efficiency of organic solar cells is usually limited by the inherent energy loss during carrier transport. Here, authors integrate bulk heterojunction organic photovoltaic with vertical field effect transistor, leading to reduced energy loss below 0.2 eV as controlled by the gate voltage.