Photoluminescence Study Of Pr3+ Doped Caga2s4 In Wide Excitation Intensity And Temperature Range

The photoluminescence (PL) of CaGa2S4:Pr3+ chalcogenide semiconductor compound is studied. The PL spectrum consists of a set of intense sharp lines at 494, 631, 654, and 741nm, formed by intra-4f transitions of Pr3+ ions. The energy level diagram of CaGa2S4:Pr3+ is proposed. A broad structural band in the PL excitation spectra in the range of 270-360nm is assumed with superposition of host related and 4f(2)-> 4f(1)5d(1) direct excitation transition bands whereas a sharp line at 456nm-with H-3(4)-> P-3(2) direct excitation. The PL decays at intensive emission lines at room temperature were found to obey nonexponential law with time constant in the range of 1.1-2.1 mu s for fast decay component and of 4.5-6.3ms for slow one. Thermal quenching by only 50% and 75% of the PL intensity of CaGa2S4:Pr3+ with 7 and 3at.% Pr3+ ions concentration, respectively, was obtained in the range of 10-300K. Extreme stability of PL spectra and efficiency of CaGa2S4:Pr3+ compound up to 10(5)W/cm(2) of excitation power density was achieved. Published under an exclusive license by AIP Publishing.