Joseph Yeow Wan Foong Japheth, Febriansyah Benny, Jyoti Singh Rana Prem, Ming Koh Teck, Jun Jie Tay Darrell, Bruno Annalisa, Mhaisalkar Subodh, Mathews Nripan
School of Materials Science and Engineering, Nanyang, Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
Energy Research Institute at Nanyang Technological University (ERI@N), Research Techno Plaza, X-Frontier Block Level 5, 50 Nanyang Drive, Singapore, 637553, Singapore.
ChemSusChem. 2021 Mar 22;14(6):1524-1533. doi: 10.1002/cssc.202002831. Epub 2021 Feb 16.
Surface imperfections created during fabrication of halide perovskite (HP) films could induce formation of various defect sites that affect device performance and stability. In this work, all-organic surface modifiers consisting of alkylammonium cations and alkanoate anions are introduced on top of the HP layer to passivate interfacial vacancies and improve moisture tolerance. Passivation using alkylammonium alkanoate does not induce formation of low-dimensional perovskites species. Instead, the organic species only passivate the perovskite's surface and grain boundaries, which results in enhanced hydrophobic character of the HP films. In terms of photovoltaic application, passivation with alkylammonium alkanoate allows significant reduction in recombination losses and enhancement of open-circuit voltage. Alongside unchanged short-circuit current density, power conversion efficiencies of more than 18.5 % can be obtained from the treated sample. Furthermore, the unencapsulated device retains 85 % of its initial PCE upon treatment, whereas the standard 3D perovskite device loses 50 % of its original PCE when both are subjected to ambient environment over 1500 h.
卤化物钙钛矿（HP）薄膜制备过程中产生的表面缺陷会诱导形成各种缺陷位点，影响器件性能和稳定性。在这项工作中，由烷基铵阳离子和链烷酸根阴离子组成的全有机表面改性剂被引入到HP层顶部，以钝化界面空位并提高耐湿性。使用烷基链烷酸铵进行钝化不会诱导低维钙钛矿物种的形成。相反，有机物种仅钝化钙钛矿的表面和晶界，这导致HP薄膜的疏水特性增强。在光伏应用方面，用烷基链烷酸铵进行钝化可显著降低复合损失并提高开路电压。在短路电流密度不变的情况下，处理后的样品可获得超过18.5%的功率转换效率。此外，未封装的器件在处理后保留了其初始功率转换效率的85%，而标准的3D钙钛矿器件在1500小时的环境暴露后损失了其原始功率转换效率的50%。
