The photoluminescence and thermoluminescence properties of nanoporous alumina films which processed in different annealing conditions

Abstract

The single-crystal α-Al₂O₃: C is a highly sensitivity dosimeter to ionizing radiation. However, the crystal grows requires high temperature and reducing atmospheres. Nanoporous anodic alumina is easy to fabricate, low cost, do not need these conditions of specialties and has been demonstrated a highly sensitive thermoluminescent dosimeter for ionizing radiation. In this paper, we get the nanoporous alumina films by two-step anodic oxidation. We present the photoluminescence (PL) and thermoluminescence (TL) properties of alumina films, which annealed under different temperature and atmosphere. From the photoluminescence emission spectra of nanoporous alumina films, we found that PL peak appears in the 450nm, the intensity of the PL peak increases with elevated annealing temperature and reaches a maximum value at 500°Cwhen the temperature is under 600°C. TL measurements show that the nanoporous alumina films after an annealing treatment present the strong and broad TL glow peaks at ～200°C. The TL intensity increase with the increase of annealing temperature. The nanoporous alumina films annealed in the air at 600°C have a linear dose response in the dose range of 5–1000 Gy for ⁶⁰Co gamma radiation and have the highest TL sensitivity. We compared these luminescence characteristics with crystal α-Al₂O₃: C, we found that the nanoporous alumina annealed in the different annealing conditions have the same characteristic in the luminescence. So we could try to take the place of it with a lower cost.