Developing PbSe/PbS core-shell nanocrystals quantum dots toward their potential heterojunction applications

We report in this article 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 octylamine, 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.