<p>An optoelectronic device including two spaced apart electrodes; and at least one layer containing ternary core/shell nanocrystals disposed between the spaced electrodes and having ternary semiconductor cores containing a gradient in alloy composition and wherein the ternary core/shell nanocrystals exhibit single molecule non-blinking behavior characterized by on times greater than one minute or radiative lifetimes less than 10 ns.</p>