The effect of particle size on the radiation dose response of luminescence signals from nanophosphors

The development and study of new nanomaterials for luminescence dosimetry is an active research area in materials science, with new nanomaterials introduced for both thermoluminescence dosimetry (TLD), and optically stimulated dosimetry (OSLD). Experimental work shows that the radiation dose response of luminescence signals from nanomaterials depends on the particle size, however there have been no quantitative descriptions of these particle size effects. In this paper we use the defect interaction model (DIM) to describe the effect of particle size on the dose response of luminescence signals from nanodosimetric materials. The model evaluates the variation of the luminescence signal with the particle size from the nanoregion of 10–100 nanometers, up to the microregion with diameters of tens of micrometers. The model describes in a quantitative manner the following experimental observations: (a) An increase of the luminescence output as the particle size increases, (b) The nanoparticle dose response has a larger linear range than the corresponding microparticle dose response (c) The nanoparticle luminescence output saturates at a larger dose than the corresponding microparticle dose response.