Structural and optoelectronic properties of glucose capped Cu doped ZnO/ Zn(OH)2 nanosheets

Abstract

Oxides of nanosheets are currently drawing much attention for their unique properties and wider potential applications. Copper (Cu) doped ZnO/ Zn(OH)2 nanosheets are synthesised by CBD method in glucose matrix. The structural, optical and electrical properties of the samples are investigated through XRD, HRTEM, UV-Visible, Pl spectroscopy and I-V measurements. XRD shows the formation of hexagonal ZnO along with Zn(OH)2 traces. Porous, transparent nanosheets having width around 3nm and nanoparticles of average size 2nm-5nm, superlattice structures are found in HRTEM images. Cu dopant may play a key role in bringing such a superlattice structure that enhances the transparency in the sheets. Formation of triangular lamina of Cu doped ZnO/ Zn(OH)2 nanosheets are confirmed by HRTEM images. EDS spectrum confirms the presence of zinc, oxygen and copper elements in CZO sample. PL spectra yield intense green emission peaks at 522.41nm which can be exploited to fabricate green LED. UV-Visible study shows band gap values as 3.70eV, 3.75eV and 3.78eV particularly for nanosheets with increasing doping concentration of copper in ZnO. The electrical conductivity is found to increase with the doping level. A correlation has been expected between the optoelectronic properties and nanosheets which are governed by superlattice structure.