Impact of a polystyrene-based passivating interlayer on hybrid polymer/ZnO nanowire heterojunctions

33rd International Conference on the Physics of Semiconductors

Bley, S.^1 ; Castro-Carranza, A.^1 ; Tansey, E.^1 ; Seemann, W.^1 ; Gutowski, J.^1

Institute of Solid State Physics, Semiconductor Optics Group, University of Bremen, Bremen

28359, Germany^1

关键词: Deep level emission;    Hybrid polymers;    Layer thickness;    Nanowire surface;    Passivating layer;    Photoluminescence measurements;    Structural investigation;    Vertically aligned nanowires;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/864/1/012044/pdf
DOI  :  10.1088/1742-6596/864/1/012044

来源: IOP

【 摘 要 】

To improve the quality of hybrid p-polymer/n-zinc oxide (ZnO) nanowire heterojunctions a thin polystyrene (PS)-based passivating interlayer is deposited on plain aqueous-chemically grown ZnO nanowires by spin coating. The structural investigation of the PS-coated nanowires via scanning electron microscopy shows that the concentration of PS in the solution affects the thickness of the PS layer. For vertically aligned nanowires a concentration of 0.125 g in 10 ml toluene is needed to get thin homogeneous passivating layers. Photoluminescence measurements of the PS-coated nanowires show a decrease of the deep-level emission depending on the PS concentration which indicates a passivation on the nanowire surface without affecting the general optical properties of the ZnO. Current-voltage characteristics of these samples show a decreased hysteresis and an increased current with decreasing PS concentration/PS layer thickness. However, a reasonably thin layer reduces the tunnelling through trap states of the ZnO nanowires.