Controlled synthesis of S-doped ZnO nanostructures: structural and Optical properties

Syed Ghazanfar Hussain*¹ and  K. M. Bhutta²

¹Government College Gujranwala 52250, Punjab, Pakistan

²Department of Physics, Bielefeld University, Bielefeld, Germany

In recent years, significant interest has focused on the synthesis of nanoscale materials. One of the most attractive classes of materials for functional nanodevices is semiconductors. Various techniques have been reported for the synthesis of semiconducting nanostructures. In particular ZnO with a wide direct band gap (Eg) of 3.37 eV at room temperature has attracted attention because of its possible application in optoelectronics, microelectronics, and biomedical sciences such as light-emitting diodes, nanolasers, light and gas sensors, transducers, dye-sensitized solar cells, varistors, and photocatalyst. Now, searching new structures, properties and applications of ZnO has become one of the most important fields. The doping of ZnO is a research topic of considerable interest in its own right, but the discussions are still limited. Oxygen and sulfur have many common physical and chemical properties due to a similar structure of their electronic shells. In addition, the band gap engineering might be possible because of larger band gap of ZnS than ZnO.

In this work, several kinds of ZnO and S-doped ZnO nanostructures have been synthesized in a controlled manner from one dimensional to three dimensional nanostructures including hierarchical nanostructures via chemical vapor deposition (CVD). For S-doped ZnO nanostructures, Zinc oxide and iron sulfide were used as zinc and sulfur sources, respectively. These nanostructures have been synthesized on silicon, quartz and steel alloy substrates and investigated their structural and optical properties. Morphologies of these nanostructures depend upon source temperature, deposition temperature, gas flow rate, the ratio between source materials and the nature of substrate. Room-temperature photoluminescence (PL) spectra of the synthesized products showed three PL peaks in the ultraviolet, blue and green emission regions. The peaks were shifted towards high energy by sulfur doping. The growth processes of the synthesized nanostructures were proposed based on experimental results.

Keywords: Nanostructures; Inorganic compounds; Chemical vapor Deposition; Electron microscopy; X-ray diffraction; Optical properties

*Corresponding Author

Syed Ghazanfar Hussain

Ph. No. +92 323 7460640

E-mail: sgh250@yahoo.com