Bae Seunghwan, Jo Jea Woong, Lee Phillip, Ko Min Jae
Photo-Electronic Hybrids Research Center , Korea Institute of Science and Technology (KIST) , Seoul 02792 , Republic of Korea.
Department of Energy and Materials Engineering , Dongguk University-Seoul , Seoul 04620 , Republic of Korea.
ACS Appl Mater Interfaces. 2019 May 15;11(19):17452-17458. doi: 10.1021/acsami.9b03929. Epub 2019 Apr 30.
To realize a high-efficiency perovskite solar cell (PSC), it is critical to optimize the morphology of the perovskite film for a uniform and smooth finish with large grain size during film formation. Using a chemical compound as an additive to the precursor solution has recently been established as a promising method to control the morphology of the perovskite film. In this study, we propose a new method to achieve an improved morphology of the methylammonium lead iodide perovskite film by simultaneous addition of dimethyl sulfoxide (DMSO) and methoxyammonium salt (MeO) (dual additives). We demonstrated that an appropriate amount of the MeO additive helps the precursors form a stable intermediated PbI-DMSO adduct during film formation and enlarges the perovskite grains by retarding the kinetics of conversion of the adduct to the perovskite. Furthermore, we experimentally observed that the optical band gaps and crystal structures of perovskite films are reasonably unaffected by the MeO additive because MeO is almost eliminated during annealing. By optimizing the amount of MeO, we achieved improved device performances of the PSCs with a high power conversion efficiency of 19.71% that is ∼15% higher than that obtained for the control device (17.15%).
为了实现高效的钙钛矿太阳能电池（PSC），在成膜过程中优化钙钛矿薄膜的形貌以获得均匀、光滑且晶粒尺寸大的表面至关重要。最近，使用一种化合物作为前驱体溶液的添加剂已被确立为一种控制钙钛矿薄膜形貌的有前景的方法。在本研究中，我们提出了一种新方法，通过同时添加二甲基亚砜（DMSO）和甲氧基铵盐（MeO）（双添加剂）来改善甲基碘化铅钙钛矿薄膜的形貌。我们证明，适量的MeO添加剂有助于前驱体在成膜过程中形成稳定的中间产物PbI - DMSO加合物，并通过延缓加合物向钙钛矿转化的动力学来增大钙钛矿晶粒。此外，我们通过实验观察到，由于MeO在退火过程中几乎被消除，钙钛矿薄膜的光学带隙和晶体结构不受MeO添加剂的合理影响。通过优化MeO的用量，我们实现了PSC器件性能的提升，功率转换效率高达19.71%，比对照器件（17.15%）高出约15%。
