Enhancing the Performance of Organic Solar Cells by Introducing Graphene-based Hole Transfer Layer

• Key Words:Organic solar cells;Competition - Conducting polymers - Costs - Electron transport properties - Graphene - Graphene oxide - Hole mobility - Light transmission - Optical properties - Solar energy - Stability - Transmission electron microscopy
• Abstract:In recent years, organic solar cells (OSCs) has aroused numerous attention thanks to their effective utilization of solar energy and competitive advantages, like low-cost, flexibility, portability and lightweight. Typical OSCs are composed of three parts, namely photoactive layer, interfacial layers (electron transport layer and hole transport layer), and electrodes. Among them, interfacial layers exhibit significant impact on the performance of OSCs device, and appropriate interface layer will be ecceedingly beneficial for the charge extraction and light transmission of the OSCs. Nevertheless, the majority of interfacial layers materials suffer from complex synthnsis approach, high-cost and poor stability, hindering the commercialization of OSCs. Accordingly, it is still a great challenge to design solution-processable, low-cost, highly stably and effective OSCs. In this work, Hummers method was employed to synthesize graphene oxide (GO), hole transport layer for OSCs, aiming at enhancing the performance and stability of OSCs. The morphology and structure of GO was characterized by means of transmission electron microscope (TEM), X-ray electron diffraction (XRD), Raman spectroscope; the optical properties of GO was analyzed by ultraviolet-visible spectrophotometry (UV-Vis); and the performance of OSCs device was evaluated by J-V test. The GO-based OSCs devices with PBDT-BDD: PC<inf>71</inf>BM as active layer held a power conversion efficiency (PCE) of 7.97%, similar to the conventional PEDOT: PSS-based devices (7.9%). Meanwhile, the GO-based OSCs devices showed a phenomenal increase in stability compared with the conventional one. The former preserved 83% of its original PCE value after storage for 80 d, while the latter remained only 45% of original PCE. Apparently, it can be concluded that GO is a promising hole transport layer material for OSCs, which contributes for the realization of high stability, and low-cost OSCs.<br/> © 2019, Materials Review Magazine. All right reserved.
• Volume:33
• Issue:6
• Translation or Not:no