title: PMMA interlayer-modulated memory effects by space charge polarization in resistive switching based on CuSCN-nanopyramids/ZnO-nanorods p-n heterojunction.
abstract: Resistive switching (RS) devices are commonly believed as a promising candidate for next generation nonvolatile resistance random access memory. Here, polymethylmethacrylate (PMMA) interlayer was introduced at the heterointerface of p-CuSCN hollow nanopyramid arrays and n-ZnO nanorod arrays, resulting in a typical bipolar RS behavior. We propose the mechanism of nanostructure trap-induced space charge polarization modulated by PMMA interlayer. At low reverse bias, PMMA insulator can block charges through the heterointerface, and V(-)Cu and V(+)o trapped states are respectively created on both sides of PMMA, resulting in a high resistance state (HRS) due to wider depletion region. At high reverse bias, however, electrons and holes can cross PMMA interlayer by Fowler-Nordeim tunneling due to a massive tilt of energy band, and then inject into the traps of ZnO and CuSCN, respectively. V(+)Cu and V(-)O trapped states are created, resulting in the formation of degenerate semiconductors on both sides of PMMA. Therefore, quantum tunneling and space charge polarization lead to a low resistance state (LRS). At relatively high forward bias, subsequently, the trapped states of V(-)Cu and V(+)o are recreated due to the opposite injection of charges, resulting in a recovery of HRS. The introduction of insulating interlayer at heterointerface, point a way to develop next-generation nonvolatile memories.
authors.affiliation: School of Materials Science and Engineering, Nanchang University, Jiangxi 330031, P. R. China.|Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Jiangxi 330031, P. R. China.
authors.forename: Baochang
authors.initials: B
authors.lastname: Cheng
authors.affiliation: School of Materials Science and Engineering, Nanchang University, Jiangxi 330031, P. R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhao
authors.affiliation: School of Materials Science and Engineering, Nanchang University, Jiangxi 330031, P. R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Xiao
authors.affiliation: School of Materials Science and Engineering, Nanchang University, Jiangxi 330031, P. R. China.
authors.forename: Qiangsheng
authors.initials: Q
authors.lastname: Cai
authors.affiliation: School of Materials Science and Engineering, Nanchang University, Jiangxi 330031, P. R. China.
authors.forename: Rui
authors.initials: R
authors.lastname: Guo
authors.affiliation: School of Materials Science and Engineering, Nanchang University, Jiangxi 330031, P. R. China.
authors.forename: Yanhe
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: School of Materials Science and Engineering, Nanchang University, Jiangxi 330031, P. R. China.
authors.forename: Shuijin
authors.initials: S
authors.lastname: Lei