Time-resolved spectroscopy of Fe3+d-d transition in bulk ZnSe polycrystal

We report temperature dependent time-resolved photoluminescence studies of Fe3+ in ZnSe polycrystals over 10–300 K temperature ranges fabricated by the post growth thermal diffusion technique. The d-d transitions of Fe3+ assigned to the 4T2(G)→6A1(S) and 4T1(G)→6A1(S) transitions are clearly identified at 528 and 627 nm, respectively, at 10 K. The observed emission peaks in the near bandgap region are red-shifted from 439 to 463 nm as the temperature increases, resulting in a temperature coefficient of 10.21×10−4 eV/K and Debye temperature = 336 K fitted by the Varshni equation. The radiative lifetime at 528 nm by time-resolved photoluminescence is evaluated as τrad = 774 ± 4 ps, activation energy (ΔEa) = 717.2 cm−1, and relaxation time rate (1/W0) = 3.1 ps.