Study on the structural and physical properties of ZnO nanowire arrays grown via electrochemical and hydrothermal depositions

Abstract : We report here the systematic study of well controlled ZnO nanowire arrays grown via two different chemical ways: electrodeposition and hydrothermal method, which are frequently used for low cost synthesis of ZnO nanowire arrays. Both methods consist of two elaboration steps: a seed layer ZnO was first deposited on the substrate and then the growth of the ZnO nanowire arrays on the seed layer was performed. SEM observations show a similar morphology, while DRX and Raman spectra revealed a preferred orientation of ZnO nanowires towards the c-axis. High resolution TEM analysis showed excellent monocrystallinity of the nanowire. A p-n junction structure based on above two kinds of nanowire arrays with a p-CuSCN layer was fabricated and their photoluminescence (PL) and conductance were measured in comparison. PL measurements demonstrated a higher defects concentration in ZnO nanowires obtained by hydrothermal method which leads to a very high current in the corresponding p-n junction with the p-CuSCN layer. This property is very important in prospective to future applications such as photovoltaic cell, nanogenerator or gas sensor.