Cadmium- and zinc-alloyed Cu–In–S nanocrystals and their optical properties

Cadmium (Cd)- and zinc (Zn)-alloyed copper–indium–sulfide (Cu–In–S or CIS) nanocrystals (NCs) several nanometers in diameter were prepared using thermal decomposition methods, and the effects of Cd and Zn on optical properties, including the tuning of NC photoluminescence (PL) wavelength and quantum yield (QY), were investigated. It was found that incorporation of Cd into CIS enhances the peak QY of NCs whereas Zn alloying diminishes the peak. In contrast with Zn alloying, Cd alloying does not result in a pronounced luminescence blue shift. The further PL decay study suggests that Cd alloying reduces surface or intrinsic defects whereas alloying with Zn increases the overall number of defects