Developing PbSe/PbS core-shell nanocrystals quantum dots (NQDs) for NQD/silicon heterojunctions

We report in this paper the epitaxial growth of PbS shells over PbSe nanocrystal quantum dots (NQDs) with monolayer-precision. The core-shell infrared NQDs were ligand-exchanged with short-chain octadmine, and the photoluminescence efficiency of the surface-engineered core-shell nanoparticles was substantially higher than that of the plain core structures undergoing the same surface processing, which reveals less ligand-dependence and enhanced chemical robustness in the core-shell NQDs. The reported results could potentially open up the possibility of incorporating semiconductor infrared NQDs in the silicon matrix to develop all-inorganic light emitting heterojunctions on silicon substrates.