We developed a novel cation exchange method to prepare the alloyed semiconductors. A series of self–assembled magnesium doped zinc oxide (MgxZn1–xO) particles were synthesised by varying the molar ratios of Mg precursor Mg5(CO3)4(OH)2•4H2O to Zn precursor ZnAc2•4H2O from 1:1 to 3:1 at different cation exchange time. Powder X–ray Diffraction (XRD) indicates that the samples are a mixture of hexagonal and cubic phases. The UV–visible (UV–vis) absorption spectra show that the band gap of MgxZn1–xO particles can be readily tuned by optimising the cation exchange time and the molar ratio of precursors. The morphology of MgxZn1–xO particles was observed by Scanning Electron Microscopy (SEM).
Keywords: wet cation exchange, band gap, UV–visible absorption, semiconductor alloys, zinc oxide, ZnO, magnesium salts, nanocrystals, microstructure, nanotechnology