Thermoluminescence Characteristics of Alpha/Gamma Irradiated-Aluminum Nitride

Abstract

Aluminum nitride doped with unintentional impurities was synthesized using the NH₄Cl(s)-assisted vapor-phase reaction method. X-ray diffraction (XRD) confirmed the formation of the hexagonal wurtzite phase with lattice parameters a = 3.111 Å and c = 3.978 Å. Energy-dispersive spectroscopy (EDS) detected the presence of Al, N, C, O, Si, and Fe in the aluminum nitride. Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy confirmed characteristic vibrational modes, further supporting the crystalline structure. Photoluminescence (PL) analysis revealed two excitation peaks at 280 and 335 nm, associated with C_NSi_Al, V_Al3O_N, and C_NV_N complex defects. The emission spectrum exhibited a predominant peak at 405 nm, in agreement with previous reports, suggesting a correlation with V_Al2O_N defects. Thermoluminescence (TL) measurements showed glow curves with peaks at 460, 525, and 600 K, confirmed through second derivative and deconvolution analysis. Activation energy values (0.69 and 0.45 eV) align with those reported for Si_Al defects. The TL response displayed saturation at approximately 140 Gy, with the third peak exhibiting a linear response in the range of 12.6–136 Gy. These results highlight the potential of AlN for TL applications, emphasizing the role of unintentional impurities in defect formation and luminescence properties.