Alpha sensing, NIR to green light emission in Er3+ doped PbWO4 nanoparticles with modification of calcination atmosphere

Abstract

[EN] In this study, various concentrations (0.5, 1, and 1.5 at%) of Er3+ PbWO4 nanoparticles (PWO: Er NPs) were prepared using a co-precipitation procedure, and the effect of the calcination atmosphere (air and argon) on the luminescence properties and scintillation responses were investigated. Different characterization analyses were carried out to study the structural and optical characteristics of prepared samples. We found evidence of the transformation of the PWO Scheelite structure into a non-centered group, which effectively influences the symmetry properties of the structure and subsequently its luminescence and sensing properties. Both Ar atmosphere and Er concentration contribute to the distortion of the scheelite structure and the symmetry breaking. However, with increasing dopant concentrations, the lattice becomes more homogeneously distorted, causing the structure to re-symmetrize and, as a result, the intensity of luminescence increases, particularly magnetic dipolar (MD) transitions that correspond to NIR emission. The ideal conditions are given when the impurity percentage reaches 1.5 at%, in the Ar atmosphere. Our PWO: Er (1.5 at%-Ar) sample had a maximum count rate of 1388 and 2082 and detection efficiency of 0.216 and 0.170 cps/Bq under Am-241 sources with 0.22 and 0.26 mu c activities, respectively. By exceeding the efficiency of the commercial ZnS(Ag), it showed promising potential for practical applications in future optoelectronic domains.