The effect of nitrogen ion implantation on the structural, optical and electrical properties of ZnSe thin films

Zinc selenide thin films were deposited onto well-cleaned glass and silicon substrates using the vacuum evaporation technique under a vacuum of 3 x 10(-5) Torr. These films were implanted with mass-analysed 75 keV N+ ions at different doses ranging from 10(14) to 10(16) ions cm(-2). The composition, microstructure, surface roughness, optical bandgap and electrical properties of the as-deposited and nitrogen-implanted films were studied by Rutherford backscattering (RBS), grazing incidence x-ray diffraction (GIXRD), atomic force microscopy (AFM), Raman scattering, optical transmittance and I-V measurements. The RBS analysis indicates that the composition of the as-deposited and nitrogen-implanted films is nearly stoichiometric. The thickness of the as-deposited film is calculated as 230 nm. The structure of the as-deposited and nitrogen-implanted thin films is cubic. In the AFM analysis, the surface roughness is found to increase with an increasing dose of nitrogen ions. In the optical studies, the optical bandgap value decreases with increase of the N+ dose. The prepared device exhibits a very good response in the visible region.