Morphology dependent luminescence from CdS nanostructures

One dimensional CdS nanostructures of different morphologies (nanowires, nanorods and nanobelts) and sizes were synthesized by a simple one step thermal evaporation of CdS powder using Au as catalyst. By controlling various experimental parameters such as temperature and position of the substrates in the furnace, different shapes of CdS nanostructures were fabricated. Morphology, size and structure were determined by scanning electron microscopy, X-ray powder diffraction and transmission electron microscopy. Room temperature photoluminescence spectra of all samples reveal a weak green emission corresponding to band edge emission and strong red emission corresponding to surface defects. Morphology dependent variations in intensities of band edge and defect related emissions were observed.

► Growth parameters are found to control the dimensionality of the CdS nanostructure.
► Morphology dependent luminescence is observed.
► The variant emissions are due to surface defects of nanostructures.