Size-dependent photoluminescent properties of uncapped CdS particles prepared by acoustic wave and microwave method

CdS particles with crystallite size of 5–12 nm have been prepared via acoustic wave stimulated (sonochemical) route and microwave initiated combustion method. X-ray line broadening and transmission electron microscopy (TEM) suggest that sonochemical powders are more amorphous (5–10 nm) compared to microwave-synthesized sulphides (10–15 nm). The photoluminescent (PL) properties of powders with size <10 nm show a clearly blue shifted, resolved emission with full-width at half-maxima (FWHM) ∼100 nm, while powders with size >15 nm show dominant blue to green narrow emission with FWHM ∼60 nm. The mechanistic details of the synthetic route appear to affect the morphology and consequently the PL properties to a significant extent.