Negatron effects in CdSe1 − xTex and ZnS1−xSex films

• Published in: Surface investigation, x-ray, synchrotron and neutron techniques x-ray, synchrotron and neutron techniques, 2014, Vol.8 (1), p.131-137
• Main Authors: Jafarov, M. A., Nasirov, E. F., Mamedova, S. A., Mekhtiev, R. F.
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Materials Science; Surfaces and Interfaces; Thin Films
• ISSN: 1027-4510; 1819-7094
• DOI: 10.1134/S102745101306027X

Various negatron effects in films of alloys of II–VI compounds deposited from solutions as a function of the deposition mode and heat treatment are studied. It is found that the negative photocapacitance effect, which was first discovered in ZnS 1− x Se x films, and the slowly relaxing negative photoelectric effects, which are caused by the transition of electrons located in a nanoscale surface layer from the shallow energy levels of trapping centers to deeper levels with a lower polarizability and by the presence of nanoscale clusters in these materials, which play the role of a “reservoir” for minority charge carriers, occur according to a single mechanism. A model to explain the basic laws of negative photoconductivity in CdSe 1 − x Te x films deposited from a solution is proposed. Negative residual conductivity is explained in terms of double-barrier relief model, while negative differential photoconductivity is attributed to the presence of nanoscale electric domains.