Photoluminescence properties of ZnGa2O4:Mn powder phosphors

The results of a systematic photoluminescence study of ZnGa2O4:Mn powder phosphor are reported. At room temperature this phosphor exhibits bright green luminescence with a spectral peak at 2.46 eV and Commission International de l’Eclairage chromaticity coordinates of x=0.073 and y=0.696. At low temperatures the luminescence was found to consist of three components assigned to the 4T1–6A1 inner transition of the 3d electrons of Mn2+ ions located on three different sites of the host crystal. Selective excitation and lifetime measurements were used to investigate the assignment of these features. The photoluminescence lifetime showed a single exponential decay of about 4 ms and at T=1.6 K an optical-phonon-related fine structure [Ephonon=(8.2±0.2) meV] of the main photoluminescence line was observed.