Zn1–xCdxO Microtubes: Synthesis and Optical Properties Using Direct Microwave Irradiation

Hexagonal Zn1–xCdxO microtubes with CdO contents (x = 0, 1, 3 and 5 %) have been successfully synthesized via direct microwave irradiation. Field emission scanning electron microscopy (FE-SEM), UV–vis spectroscopy, photoluminescence (PL), and energy-dispersive spectrometer (EDS) were employed to characterize the Zn1–xCdxO microtubes. Zn1–xCdxO microtubes have an average diameter of 140 µm, wall thickness of 2~4 µm and length of about 250 µm. UV–vis studies showed that the optical band gap of ZnO microtube (3.27 eV) was reduced to 3.20 eV for Zn0.97Cd0.03O microtube. The PL spectra showed a strong emission peak in the visible region centered at 562.88 nm with a weak UV emission has been detected for Zn0.97Cd0.03O microtube. EDS confirms the presence of Zn and O in ZnO microtube and the absence of Cd as a doping material for CdO-doped ZnO microtubes due to the small amounts of CdO concentration