Location:
online
Date:
Yulin Geng
Comparison of ZnO Nanowires Grown on E-beam Evaporated Ag and ZnO seed layers
One dimensional (1D) Zinc Oxide (ZnO) nanowire has received much attention due to their remarkable performance in piezoelectric, optoelectronic, and electrochemical applications. In this study, ZnO nanowires with diameters ranging from 50 nm to 500 nm have been synthesized hydrothermally on Ag and ZnO seed layers deposited by electron beam evaporation. ZnO nanowires grown on hetero and homo interfaces have been studied by comparing the growth characteristics of (a) ZnO nanowires on Ag seed layer, and (b) ZnO nanowires grown on ZnO seed layer respectively. The surface morphology of as-evaporated seed layers before the nanowire growth has been investigated. Electron Backscatter diffraction (EBSD) has been employed to examine the crystallinity of ZnO nanowires. The integrity of the Ag-ZnO heterointerface has been investigated using high-resolution transmission electron microscopy (HR-TEM). The length, diameter, density, and alignment of nanowires grown on Ag and ZnO seed layers have been studied as a function of growth time from 0.5 hours to 18 hours, and precursors concentration from 5 mM to 18 mM. Furthermore, for both Ag-ZnO nanowires heterostructure and ZnO-ZnO nanowires homostructure, the role of defects in the optical properties in the wavelength range of 517 nm to 900 nm has been studied using photoluminescence (PL) spectroscopy.
Markus Ronde
Selective Vapour Etching – A key technology to realise nanoelectromechanical systems sensors
Microelectromechanical systems (MEMS) sensors have become a common sight in our daily lives. For instance, MEMS microphones are used to record our voice during Zoom calls and Teams meetings, MEMS inertia sensors in cars protect us by triggering the airbags in cases of an accident, and they make sure that the screens of our smartphones are correctly orientated at all times. But what are the potentials of reducing the size of MEMS into the nanoscale? This talk will briefly describe the potentials of nanoelectromechanical systems (NEMS) sensors and describes the main challenge in fabricating them. It will then present selective vapour etching, a potential method to overcome those fabrication barriers and will give an inside of the latest research on the subject.
