Sutanto, Albertus AdrianIgci, CansuKim, HobeomKanda, HiroyukiShibayama, NaoyukiMensi, MounirQueloz, Valentin I. E.Momblona, CristinaYun, Hyung JoongBolink, Henk J.Huckaba, Aron J.Nazeeruddin, Mohammad Khaja2021-06-082021-06-082021-06-082021-02-2210.1021/acsaem.0c02472https://infoscience.epfl.ch/handle/20.500.14299/178733WOS:000621660800025Defects of metal-halide perovskites detrimentally influence the optoelectronic properties of the thin film and, ultimately, the photovoltaic performance of perovskite solar cells (PSCs). Especially, defect-mediated nonradiative recombination that occurs at the perovskite interface significantly limits the power conversion efficiency (PCE) of PSCs. In this regard, interfacial engineering or surface treatment of perovskites has become a viable strategy for reducing the density of surface defects, thereby improving the PCE of PSCs. Here, an organic molecule, tris(5-((tetrahydro-2H-pyran-2-yl)oxy)pentyl) phosphine oxide (THPPO), is synthesized and introduced as a defect passivation agent in PSCs. The P.O terminal group of THPPO, a Lewis base, can passivate perovskite surface defects such as undercoordinated Pb2+. Consequently, improvement of PCEs from 19.87 to 20.70% and from 5.84 to 13.31% are achieved in n-i-p PSCs and hole-transporting layer (HTL)-free PSCs, respectively.text::journal::journal article::research article