Investigations on the stability of thiol stabilized semiconductor nanoparticles

Various analytical methods like analytical ultracentrifugation, UV-vis absorption spectroscopy, NMR spectroscopy, and powder X-ray diffraction have been applied to study the stability of thiol stabilized semiconductor nanoparticles. Reduced particle sizes were found in solution at low concentrations. Most probably the assumed covalently bound thiols desorb from the surface of the particles, leaving behind vulnerable unstabilized particles that might even undergo continuous decay over time. Additionally, breaking of the intra ligand S-C bond could be demonstrated, presenting a cadmium sulfide particle synthesis introducing sulfur only by the ligands without any additional sulfide ions.