Optical properties of PbS/CdS superlattices grown by pulsed laser evaporation

PbS/CdS superlattices have been grown on BaF2, CaF2, Si and glass subtrates. Each specimen contained 10 to 23 pairs of the PbS/CdS layers. Absorption spectra of the structures have shown specific steps. The energy distribution of the steps has been analysed using models of Tipe-I and Tipe-II superlattices. Experimental results have been shown to follow the theoretical values of the steps for Tipe-II superlattices. This gives a foundation for classifying PbS/CdS superlattices as Tipe-II.