Cadmium Reduced QDs for Superior Brightness and Stability within RoHS Limits

J. Niehaus, S. Becker
Fraunhofer IAP-CAN,

Keywords: quantum dot, RoHS, emitter, display, lighting


Here we report about a new developed giant shell quantum dot particle system combining the best of both worlds, the cadmium containing and the cadmium free QDs. These QDs have a cadmium content below 3 %. Compared to the old CdSe-based system with cadmium contents over 70 %, this makes it easy to use a high concentration of QDs but still fulfilling the RoHS limits. While the quantum yields are comparable to the all cadmium systems (close to 1), the FWHM is even better than those of the all Cadmium particles. In most cases, the FWHM is even below 20 nm! The particles show a high absorption in the blue, which makes them ideal for color converters, while the giant shell ensures a high stability. The characterization of the GSQD particles will be shown (TEM, absorption, emission, QY, Cd content, stability etc) as well as examples for their use in different applications like active material in QLEDs and polymer composites.