title: van der Waals Heterojunction Devices Based on Organohalide Perovskites and Two-Dimensional Materials.
abstract: The recently emerged organohalide perovskites (e.g., CH3NH3PbI3) have drawn intense attention for high efficiency solar cells. However, with a considerable solubility in many solvents, these perovskites are not typically compatible with conventional lithography processes for more complicated device fabrications that are important for both fundamental studies and technological applications. Here, we report the creation of novel heterojunction devices based on perovskites and two-dimensional (2D) crystals by taking advantage of the layered characteristic of lead iodide (PbI2) and vapor-phase intercalation. We show that a graphene/perovskite/graphene vertical stack can deliver a highest photoresponsivity of ∼950 A/W and photoconductive gain of ∼2200, and a graphene/WSe2/perovskite/graphene heterojunction can display a high on/off ratio (∼10(6)) transistor behavior with distinct gate-tunable diode characteristics and open-circuit voltages. Such unique perovskite-2D heterostructures have significant potential for future optoelectronic research and can enable broad possibilities with compositional tunability of organohalide perovskites and the versatility offered by diverse 2D materials.
authors.affiliation: Department of Materials Science and Engineering, ‡Department of Chemistry and Biochemistry, and §California NanoSystems Institute, University of California , Los Angeles, California 90095, United States.
authors.forename: Hung-Chieh
authors.initials: HC
authors.lastname: Cheng
authors.affiliation: Department of Materials Science and Engineering, ‡Department of Chemistry and Biochemistry, and §California NanoSystems Institute, University of California , Los Angeles, California 90095, United States.
authors.forename: Gongming
authors.initials: G
authors.lastname: Wang
authors.affiliation: Department of Materials Science and Engineering, ‡Department of Chemistry and Biochemistry, and §California NanoSystems Institute, University of California , Los Angeles, California 90095, United States.
authors.forename: Dehui
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Materials Science and Engineering, ‡Department of Chemistry and Biochemistry, and §California NanoSystems Institute, University of California , Los Angeles, California 90095, United States.
authors.forename: Qiyuan
authors.initials: Q
authors.lastname: He
authors.affiliation: Department of Materials Science and Engineering, ‡Department of Chemistry and Biochemistry, and §California NanoSystems Institute, University of California , Los Angeles, California 90095, United States.
authors.forename: Anxiang
authors.initials: A
authors.lastname: Yin
authors.affiliation: Department of Materials Science and Engineering, ‡Department of Chemistry and Biochemistry, and §California NanoSystems Institute, University of California , Los Angeles, California 90095, United States.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, ‡Department of Chemistry and Biochemistry, and §California NanoSystems Institute, University of California , Los Angeles, California 90095, United States.
authors.forename: Hao
authors.initials: H
authors.lastname: Wu
authors.affiliation: Department of Materials Science and Engineering, ‡Department of Chemistry and Biochemistry, and §California NanoSystems Institute, University of California , Los Angeles, California 90095, United States.
authors.forename: Mengning
authors.initials: M
authors.lastname: Ding
authors.affiliation: Department of Materials Science and Engineering, ‡Department of Chemistry and Biochemistry, and §California NanoSystems Institute, University of California , Los Angeles, California 90095, United States.
authors.forename: Yu
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Materials Science and Engineering, ‡Department of Chemistry and Biochemistry, and §California NanoSystems Institute, University of California , Los Angeles, California 90095, United States.
authors.forename: Xiangfeng
authors.initials: X
authors.lastname: Duan
keywords: 2D materials; Organohalide perovskites; WSe2; optoelectronic devices; van der Waals heterostructures