title: CH3NH3PbI3-xClxunder Different Fabrication Strategies: Electronic Structures and Energy-Level Alignment with an Organic Hole Transport Material.
abstract: We report a photoelectron spectroscopy study on the electronic structure of CH3NH3PbI3-xClxthin films fabricated by physical evaporation from CH3NH3I and PbCl2precursors, including (1) simultaneously evaporation and (2) sequential evaporation. The results are compared with CH3NH3PbI3-xClxmade using conventional solution chemistry (i.e., spin-coating). Depending on the fabrication method, CH3NH3PbI3-xClxfilms show different chemical constituents in the near-surface region, leading to disparities in their energetic levels. The chemical identities of the surface species are revealed by an in situ study on the sequentially evaporated film. Moreover, air-exposure treatment also greatly alters the energetic levels of the film. Using hole transport layer of N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (NPB) as a model system, we find that the energy-level alignment with the spin-coated film after air exposure is most suitable for efficient hole transport.
authors.affiliation: Jiangsu Key Laboratory for Carbon-based Functional Materials and Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.|Institut für Physik, Humboldt-Universität zu Berlin , Brook-Taylor Straße 6, 12489 Berlin, Germany.
authors.forename: Rongbin
authors.initials: R
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory for Carbon-based Functional Materials and Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Wu
authors.affiliation: Jiangsu Key Laboratory for Carbon-based Functional Materials and Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Jiangsu Key Laboratory for Carbon-based Functional Materials and Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
authors.forename: Jitao
authors.initials: J
authors.lastname: Li
authors.affiliation: Jiangsu Key Laboratory for Carbon-based Functional Materials and Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Shen
authors.affiliation: Jiangsu Key Laboratory for Carbon-based Functional Materials and Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory for Carbon-based Functional Materials and Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
authors.forename: Liangsheng
authors.initials: L
authors.lastname: Liao
authors.affiliation: Jiangsu Key Laboratory for Carbon-based Functional Materials and Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
authors.forename: Lijia
authors.identifier: http://orcid.org/0000-0003-2439-0739
authors.initials: L
authors.lastname: Liu
authors.affiliation: Jiangsu Key Laboratory for Carbon-based Functional Materials and Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
authors.forename: Steffen
authors.initials: S
authors.lastname: Duhm
keywords: air exposure; electronic structure; formation mechanism; hole transport; perovskite; photoelectron spectroscopy