Studies on growth morphology, UV absorbance and luminescence properties of sulphur doped ZnO nanopowders synthesized by the application of ultrasound with varying input power

• Sonochemical synthesis of ZnO:S nanorods and multipodes with varying input power of ultrasound.
• Sonication time linearly decreases with increase in applied power.
• Precipitation, growth and morphology depend upon input power of ultrasound.
• Nanorods and multipodes of ZnO:S are oriented along c-axis.
• Enhanced UV absorption of ZnO:S nanopowder for sunscreen applications.

Sulphur doped ZnO nanopowders have been prepared by sonochemical method in continuous (CS) and pulsed (PS) modes. Precipitation time was found to vary with input power of applied ultrasound. X-ray diffraction studies show the formation hexagonal wurtzite phase of nano ZnO but variation in size, strain and lattice parameters was observed in the samples synthesized through CS and PS modes with different input power. Surface morphology of the samples changed significantly with input power of the pulse as observed from scanning electron microscopic results. Well defined and c-axis oriented nanorods and multipodes were observed with power setting of 187.5 W whereas in all other cases no definite morphology was observed. UV absorption studies show higher value of absorbance for ZnO:S. Further, the absorption band becomes sharp for the samples prepared with power setting of 225 W. PL spectra show several bands due to different transitions in the region of 400–780 nm which have been explained in the light of excitonic and defect induced transitions in ZnO.