Optical properties of Sn-doped zinc aluminophosphate glasses: sensitive thermally stimulated luminescence for radiation detection

In this study, we have synthesized xSnO₂–50Zn₃(PO₄)₂–50Al(PO₃)₃ glasses (x=0, 0·1, 0·3, 1·0, 3·0 and 10 mol%) by the conventional melt quenching method, and investigated the optical, photoluminescence (PL), scintillation and storage luminescence properties. The Sn-doped samples showed PL with a broad emission across 300–700 nm due to s¹ p ¹ → s² transitions of Sn²⁺. The quantum yield was the highest for the 10 mol% doped sample (53%), which decreased with decreasing dopant concentration. The lifetime was strongly dependent on the emission wavelength, in which the lifetime decreased with decreasing the wavelength. The scintillation had almost the same spectral features as those of PL, and the 10 mol% doped sample showed the highest intensity. The thermally stimulated luminescence (TSL) glow curves had a peak around 170°C. The sensitivity of TSL to x-ray dose was the highest for the 0·3 mol% Sn-doped sample unlike PL and scintillation, and it decreased with increasing the concentration of Sn. In addition, we confirmed that 0·1, 0·3 and 1·0 mol% Sn-doped samples have a sensitivity as low as 0·1 mGy, and these responses monotonically increased with the irradiation dose over 10 Gy. The latter sensitivity is considered sufficiently high for applications in personnel protection dosimetry; therefore, we believe that the present materials have a great potential for practical applications.