High-Performance Perovskite Solar Cells Fabricated via Marangoni Effect

• Main Authors: Ji Zhong-Jia, 紀仲嘉
• Other Authors: Chan Chia-Hua
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/a4kd3k

碩士 === 國立中央大學 === 能源工程研究所 === 106 === In this study, we used Single-Step and anti-solvent methods to fabricate a MAPbI3-based perovskite solar cell. However, using the toluene as an anti-solvent will induce the "Marangoni effect" due to difference of the surface tension at the interface between the dripped solvent and the perovskite precursor. This effect will cause non-uniform distribution of the intermediate phase (MAI-PbI2-DMSO) which will form unexpected voids inside the perovskite layer leading to a low-quality perovskite film. Therefore, we introduce a simple delayed-annealing method to achieve a high-quality and high-coverage perovskite layer which can significant improve the non-uniform distribution of the intermediate phase. We use the SEM(Scanning Electron Microscope), XRD(X-ray Diffractometer), AFM (Atomic Force Microscopic) and EIS（Electrochemical Impedance Spectroscopy） to observe and analyze the quality of perovskite films. In comparison with the control sample (without delayed-annealing), the power conversion efficiency (PCE) will increase from 13.58% to 18.02% (enhanced 32.69%) with the sample annealing at 100℃ for 40 min. Moreover, to replace the traditional toxic anti-solvent and realize a rapid process of forming a high-quality perovskite film, a low-toxic anti-solvent ethyl acetate (EA) is chosen to rapidly fabricate high-quality perovskite layers with the advantages of low surface tension and high evaporation rate. After using EA as the alternative anti-solvent, the highest PCE is 16.39% with dripping the EA of 500ul. Although the PCE is lower than using traditional toluene as the anti-solvent, it’s unnecessary treating with annealing process for 40 mins to suppress the Marangoni effect which has benefits to reduce the time and cost of fabricate the perovskite solar cells. Additionally, we further incorporate with nanostructures on the FTO surface to increase the absorption of perovskite layer and contact area between FTO surface and mesoporous layer which can effectively increase the electron transport efficiency. Finally, the PCE will eventually increase to 19.29% while the sample treated with delayed-annealing method and introduced with the patterned-FTO substrate.