Probing the Cr3+ luminescence sensitization in β-Ga2O3 with ion-beam-induced luminescence and thermoluminescence
Duarte Magalhães Esteves, Ana Luísa Rodrigues, L.C. Alves, E. Alves, María Isabel Dias, Zhitai Jia, Wenxiang Mu, K. Lorenz, M. Peres
Abstract
Abstract Ion-beam-induced luminescence (IBIL) measurements were performed in Cr-doped β -Ga 2 O 3 using both protons and helium ions, showing a strong enhancement of the Cr 3+ luminescence upon ion irradiation. Theoretical modelling of the IBIL intensity curves as a function of the fluence allowed estimating the effective cross-sections associated with the defect-induced IBIL enhancement and quenching processes. The results suggest that sensitizing the Cr 3+ luminescence is more efficient for H + than for He + irradiation. Thermoluminescence (TL) studies were performed in the pristine sample, with no TL signal being observed in the spectral region corresponding to the Cr 3+ emission. In agreement with the IBIL study, upon ion irradiation (with either protons or helium ions), this TL emission is activated. Moreover, it can be quenched by annealing at 923 K for 10 s, thus revealing the role played by the defects induced by the irradiation. These results show that the irradiation-induced defects play a major role in the activation of the Cr 3+ luminescence, a fact that can be exploited for radiation sensing and dosimetry.