We investigated the negative photoconductivity (NPC) effect that was observed in a p-type Pb1-xSnxTe film for temperatures varying from 300 K down to 85 K. We found that this effect is a consequence of defect states located in the bandgap which act as trapping levels, changing the relation between generation and recombination rates. Theoretical calculations predict contributions to the NPC from both conduction and valence bands, which are in accordance with the experimental observations.

We report on the observation of the Shubnikov–de Haas oscillation in a polycrystalline ZnO/CdO heterostructure grown on a silicon substrate by a spray pyrolysis technique in temperatures below 6 K. From the analysis of these quantum oscillations, we obtained the cyclotronic effective mass, the 2D carrier concentration, and the thickness of the two-dimensional electron gas in the interface of the two layers. The results suggest that a two-dimensional electron gas is successfully obtained at the ZnO/CdO interface.

We present a systematic investigation of the morphological and magnetotransport properties of Zn1− xCd xO/CdO heterostructures managing the electronic barrier by changing x values between [Formula: see text] and [Formula: see text]. From physical parameters such as roughness and crystallite size obtained through scanning electron microscopy and x-ray diffraction, we established a correlation between the disorder degree and the amplitude of the negative magnetoresistance as well as the nature of the dominating inelastic scattering mechanisms. The magnetoresistance measurements revealed a negative amplitude for all heterostructures, which clearly shows that the weak localization effect is observed in the low temperature range. Applying the three-dimensional weak localization theory (Kawabata 3D), we extract the phase coherence length, and a relatively large value (maximum reaches 135 nm at 4.2 K) is obtained for the Zn0.05Cd0.95O/CdO heterostructure.