Structural and spectroscopic investigations of CdS/HgS/CdS quantum-dot quantum wells

Epitaxial growth in a CdS/HgS heterostructure of nanometer dimensions, prepared by methods of wet chemistry, is demonstrated. High-resolution transmission-electron microscopy is used to determine the shape and crystallinity of this system consisting of a quantum well in a quantum dot. The homogeneous absorption and fluorescence spectra are investigated by transient hole burning and fluorescence line-narrowing spectroscopy. The photophysical measurements provide evidence for charge-carrier localization within the HgS well.