Effects of electron irradiation on n-ZnS/p-Si and ZnS-Au visible-blind UV photodetectors

Zinc Sulphide (ZnS) has a direct bandgap of 3.7eV which is highly suitable for the fabrication of visible blind UV photodetectors. It can also form lattice matched heterojunction with silicon. In the present research work, we propose to fabricate two different photodetector structures based on ZnS. The first structure makes use of n-ZnS/p-Si heterojunction while the second structure is based on ZnS-Au Schottky barrier. The proposed photodiode structures are expected to possess superior UV detection characteristics, in both UV-A and UV-B spectral regions, which are highly desirable in space applications. As with all other optoelectronics devices used in space, the UV photodetectors are also susceptible to electron irradiation. Hence, it is proposed to study the effects of high energy electron irradiation on the two photodetector structures. The study is expected to reveal vital information about the nature of radiation induced defects in the photodetectors. This knowledge may prove to be useful in optimizing the photodetectors for space applications.