Jung, Kyungeun Chae, Weon-Sik Park, Yun Chang Kim, Joosun Lee, Man-Jong 2024-01-19T18:30:34Z 2024-01-19T18:30:34Z 2021-09-05 2020-01-15 1385-8947 https://pubs.kist.re.kr/handle/201004/119086 To fabricate efficient MAPbI(3) perovskites using the Lewis acid-base adduct approach, we used a Lewis base hexamethylphosphoramide (HMPA) having a high donor number (D-N), and investigated the effect of high-D-N HMPA treatment on the properties of planar MAPbI(3)-based solar cells. The main functions of the HMPA treatment were to passivate the perovskites by forming well-distributed PbI2 phases and to densify the perovskites by controlling the rate constants. The treatment with Lewis base HMPA by one-step spin coating and subsequent solvent washing promoted the formation of pinhole-free perovskite films by increasing the coordination ability of HMPA with Pb2+ adducts and controlling the nucleation and growth rates of the perovskites. In addition, treatment with various concentrations of HMPA led to the formation of a residual PbI2 phase that acted as a passivation layer, even though stoichiometric quantities of precursors were used. Through a series of advanced electron microscopy studies, the exact three-dimensional locations of the PbI2 passivation layers were determined. Furthermore, by calculating the decreased active trap concentrations and carrier densities, we verified the passivation effect of remnant PbI2. Importantly, we achieved the best power conversion efficiency of 17.09% by the controlled addition of Lewis base HMPA, thus demonstrating a much improved performance than that obtained without HMPA treatment (15.73%). English ELSEVIER SCIENCE SA LEAD IODIDE PEROVSKITE FILMS PERFORMANCE PBI2 PASSIVATION COORDINATION SOLVENT ENHANCE LINKING GROWTH Influence of Lewis base HMPA on the properties of efficient planar MAPbI(3) solar cells fabricated by one-step process assisted by Lewis acid-base adduct approach Article 10.1016/j.cej.2019.122436 1 CHEMICAL ENGINEERING JOURNAL, v.380 CHEMICAL ENGINEERING JOURNAL 380 scie scopus 000494815600035 2-s2.0-85070303787 Engineering, Environmental Engineering, Chemical Engineering Article LEAD IODIDE PEROVSKITE FILMS PERFORMANCE PBI2 PASSIVATION COORDINATION SOLVENT ENHANCE LINKING GROWTH Lewis base-acid HMPA Passivation Planar perovskite solar cells Electron microscopy