Demonstration of bulk semiconductor optical properties in processable Ag₂S and EuS nanocrystalline systems

The optical properties of two bulk nanocrystal (NC) systems, namely Ag ₂S and EuS, were analyzed. A novel solvent-free method was used to synthesize Ag₂S nanoparticles whereas thermal decomposition of a single-source precursor was used to synthesize EuS nanoparticles. The particle size distribution of both the Ag₂S and EuS nanoparticles were characterized through transmission electron microscopy (TEM). It was found that nanocrystals, which can be potentially mistaken for quantum-confined structures on the basis of anomalous absorption spectra, does not only apply to EuS. The results show that these two bulk nanocrystal systems can occupy a complementary role to quantum confined structures as another building block for the development of new technologies.