Single-crystalline MgxZn1-xO (0 <= x <= 0.25) nanowires on glass substrates obtained by a hydrothermal method: growth, structure and electrical characteristics

Abstract

Single-crystalline Mg-x-Zn1-xO(0 <= x <= 0.25) nanowires (MZONWs) were synthesized on glass substrates by a hydrothermal method using a mixture of an aqueous solution of zinc nitrate hexahydrate, magnesium nitrate hexahydrate and diethylenetriamine at temperatures that ranged from 75 to 105 degrees C. X-ray diffraction, scanning electron microscopy and transmission electron microscopy investigations were carried out to characterize the crystallinity, surface morphologies and orientations of these nanowires, respectively. These nanowires with direct band gaps ranging from 3.21 to 3.95 eV emitted ultraviolet photoluminescence from 406 to 397 nm at room temperature as the Mg content increased. Field emission measurements revealed that the turn-on electric field and threshold electric field (current density of 1 mA cm(-2)) of ZnO NWs are 1.6 and 2.1 V mu m(-1) with the value of 3340. Therefore, low temperature synthesized MZO NWs (0 <= x <= 0.25) with modulated band gaps may be applied in solar cells, light emission devices and other nanoheterojunction devices in the future.