Mobile charge carriers in heterostructured nanoparticles are relevant for applications requiring charge separation and extraction. We investigate the benchmark systems CdSe–CdS core–shell quantum dots and quantum dots in quantum rods by optical and THz pump–probe spectroscopy. We relate photoconductivity and carrier location and observe that only shell-located electrons in quantum rods contribute to an observable photoconductivity. Despite the shallow electron confinement in the quasi-type II heterostructures, core-located carriers are bound into immobile excitons that respond on external electrical fields by polarization.

We present an automated and up-scaled synthesis of giant-shell QDs (GSQD). For color conversion, these particles will be incorporated in a suitable matrix with high QD content and transferred onto a blue light LED. We will also show results of QLEDs with a thin film of GSQD as active material.