CdSe & ZnS core/shell nanoparticles generated by laser ablation of microparticles

Laser Ablation of Microparticles (LAM) is a process of nanoparticle formation in which microparticles in a flowing aerosol are continuously ablated by high-power laser pulses. For the first time, we have produced CdSe/ZnS core/shell nanoparticles using a double ablation apparatus, designed to undergo a two-step LAM process. This process can be inverted to produce ZnS/CdSe core/shell nanoparticles. The present work focuses on the range around ∼15 nm radius heterostructures and uses high-resolution transmission electron microscopy (HRTEM) to image core and shells. For smaller particles, core shell structures have been detected with energy dispersive spectroscopy (EDS) 5 nm spot size beam and fast Fourier transform (FFT) spectra. Differences in the ablation behavior were measured between the two IIB–VIA type semiconductors.