Effect of swift heavy ion irradiation on bismuth doped BaS nanostructures

We report the use of swift heavy ion irradiation as a means to tailor the luminescence properties of bismuth doped barium sulphide nanostructures. The samples were irradiated with 120 MeV Ni+9 ions at three different fluences of 1 × 1012, 5 × 1012, and 1 × 1013 ion/cm2. Structural and optical properties of pristine and irradiated samples were carried out using X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL) and UV–vis spectroscopy. X-ray diffraction (XRD) studies were used to estimate the average size of nanoparticles. The average size of the crystallites is estimated from the line widths of the diffraction pattern, while the exact size of the crystallites is estimated from the TEM micrographs. After irradiation with a fluence of 1 × 1013 ion/m2 the photoluminescence intensity increases by 42%. The indirect band gap of BaS:Bi is increased after ion irradiation.