Tseng, W.-S.W.-S.TsengJao, M.-H.M.-H.JaoHsu, C.-C.C.-C.HsuHuang, J.-S.J.-S.HuangWu, C.-I.C.-I.WuYeh, N.-C.N.-C.YehCHIH-I WU2020-06-112020-06-112017https://scholars.lib.ntu.edu.tw/handle/123456789/498028We report the long-term stability of water-sensitive hybrid perovskites CH3NH3PbI3 that were protected with monolayer graphene. This successful passivation was enabled by our development of a new water-free and polymer-free graphene transfer method. Monolayer graphene samples grown by plasma-enhanced chemical vapor deposition and transferred onto different substrates with the water/polymer-free method were found to preserve their high-quality characteristics after the transfer, as manifested by the studies of Raman, X-ray and ultraviolet photoemission spectroscopy (XPS and UPS), optical absorption, and sheet resistance. Additionally, XPS, UPS and optical absorption studies of fully graphene-covered CH3NH3PbI3 thin films showed spectral invariance even after 3 months, which was in sharp contrast to the drastic spectral changes after merely one week in control CH3NH3PbI3 samples without graphene protection. This successful demonstration of the graphene-enabled passivation and long-term stability of CH3NH3PbI3 thin films therefore opens up a new pathway towards realistic photovoltaic applications of hybrid perovskites. © 2017 The Royal Society of Chemistry.[SDGs]SDG7Electromagnetic wave absorption; Graphene; Lead compounds; Light absorption; Monolayers; Passivation; Perovskite; Perovskite solar cells; Photoelectron spectroscopy; Plasma CVD; Plasma enhanced chemical vapor deposition; Vapor deposition; Water absorption; X ray photoelectron spectroscopy; Different substrates; Long term stability; Optical absorption studies; Photovoltaic applications; Spectral change; Spectral invariances; Transfer method; Ultraviolet photoemission spectroscopy; Thin filmsjournal article10.1039/c7nr06510h2-s2.0-85038412150https://www.scopus.com/inward/record.uri?eid=2-s2.0-85038412150&doi=10.1039%2fc7nr06510h&partnerID=40&md5=5f6b64fe645ba4e5326bf5a5cf14fee2