Infrared absorption by polar optical phonons in a CdS nanocrystal array consisting of quantum dots and quantum wires

Based on the results of experimental studies, it is shown that, when the effect of size quantization on the vibratory properties of CdS nanocrystals is insignificant, the absorption spectra of nanocomposites containing CdS quantum wires and quantum dots exhibit not only the peak associated with the transverse optical phonons but also two other pronounced peaks associated with electrostatic vibration modes. When the size of nanocrystals is so small that the effect of size quantization cannot be neglected, the structure of the reflection and transmission spectra becomes much more complicated because of the contribution of the mixed longitudinal-transverse phonon modes.