Hu, JinlongWang, ChuanQiu, ShudiZhao, YichengGu, EningZeng, LinxiangYang, YuzhaoLi, ChaohuiLiu, XianhuForberich, KarenBrabec, Christoph J.Nazeeruddin, Mohammad KhajaMai, YaohuaGuo, Fei2021-06-082021-06-082021-06-082020-05-0110.1002/aenm.202000173https://infoscience.epfl.ch/handle/20.500.14299/178770WOS:000532297600009As perovskite solar cells (PSCs) are highly efficient, demonstration of high-performance printed devices becomes important. 2D/3D heterostructures have recently emerged as an attractive way to relieving the film inhomogeneity and instability in perovskite devices. In this work, a 2D/3D ensemble with 2D perovskites self-assembled atop 3D methylammonium lead triiodide (MAPbI(3)) via a one-step printing process is shown. A clean and flat interface is observed in the 2D/3D bilayer heterostructure for the first time. The 2D perovskite capping layer significantly suppresses nonradiative charge recombination, resulting in a marked increase in open-circuit voltage (V-OC) of the devices by up to 100 mV. An ultrahigh V-OC of 1.20 V is achieved for MAPbI(3) PSCs, corresponding to 91% of the Shockley-Queisser limit. Moreover, notable enhancement in light, thermal, and moisture stability is obtained as a result of the protective barrier of the 2D perovskites. These results suggest a viable approach for scalable fabrication of highly efficient perovskite solar cells with enhanced environmental stability.text::journal::journal article::research article