Effects of Radiation on II-VI Thin Films

Abstract

The need for lightweight, rugged and reliable power source in military and space applications, where devices are subjected to a variety of radiation environments, shows the importance of studying the radiation effects on some of the bulk semiconductor devices. The main objective of the present work is to study the gamma radiation effects on the prepared solar cells based on the II-VI materials. Also, to investigate their radiation sensitive parameters. Physical, optical and electrical characteristics of the II-VI materials, such as CdTe, CdS, CdSe, ZnS and ZnSe, were studied. The morphology of these materials were analyzed applying the x-ray diffraction and the EDX analysis techniques. Also, the optical characteristics were measured where the optical band gap of these materials were calculated. The current-voltage relationship of these materials were measured. From which, the activation energy was obtained from the variation of the conductivity with the temperature. CdTe was chosen, from the above compounds, to be an absorber, while CdS was chosen as a window for the proposed solar cell. Two configurations were prepared using CdS/CdTe to study some ofthe electrical properties of the cells. The two proposed samples were: the frontwall cell; with the arrangement of glass I CTO I CdS I CdTe, and backwall cell; with the arrangement of glass I Au I CdTe I CdS. The thermal evaporation method was the way of preparing these samples.