title: Enhanced field emission properties of ZnO-Ag2S core-shell heterojunction nanowires.
abstract: A simple approach to Ag2S quantum dot (QD) modification was used to tune the field emission (FE) properties of ZnO nanowire arrays (NWAs). By a simple and facile successive ionic layer adsorption and reaction (SILAR) approach, Ag2S QDs were uniformly and densely packed on ZnO nanowires (NWs) to form ZnO-Ag2S core-shell heterojunction structures. The FE properties of ZnO NWAs were effectively tuned by controlling the amount of Ag2S QDs. The turn-on field first reduces and then increases as the amount of Ag2S QDs increases, while the trend of the field-enhancement factor is inverse. This is attributed to the clustering of Ag2S QDs into nanoparticles (NPs) which cover the nanowire tips, as SILAR cycles increase.
authors.affiliation: State Key Lab of New Ceramic and Fine Processing, School of Materials Science & Engineering, Tsinghua University, Beijing 100084, China. zcli@mail.tsinghua.edu.cn.
authors.forename: Guojing
authors.initials: G
authors.lastname: Wang
authors.forename: Mingyang
authors.initials: M
authors.lastname: Li
authors.forename: Chienhua
authors.initials: C
authors.lastname: Chen
authors.forename: Shasha
authors.initials: S
authors.lastname: Lv
authors.forename: Jiecui
authors.initials: J
authors.lastname: Liao
authors.forename: Zhengcao
authors.initials: Z
authors.lastname: Li