Programmable assembly of CdTe quantum dots into microstructures by femtosecond laser direct writing

Abstract

Reported here is the programmable assembly of CdTe quantum dots (QDs) into various pre-designed microstructures by using a femtosecond laser direct writing (FsLDW) technique. As nanobuilding blocks, CdTe QDs could be driven by a focused femtosecond laser beam to construct arbitrarily-shaped micropatterns with high resolution (∼170 nm). The optical properties of pristine CdTe QDs were well inherited after the FsLDW induced programmable assembly, which has been confirmed by the luminescence spectrum and the high resolution transmission electron microscope (HR-TEM) image of the assemblies. By using this technique, the CdTe QDs microstructures were integrated within microfluidic devices, which showed the capability of qualitative on-chip detection of heavy metal ions. The FsLDW induced assembly of QDs may open up a new way for the designable assembly of QDs towards the flexible fabrication and integration of QDs-based microdevices.