Photoluminescence and thermal stability of Mn2+ co-doped SrSi2O2N2:Eu2+ green phosphor synthesized by sol-gel method

Eu2+ and Mn2+ co-doped SrSi2O2N2 phosphors were firstly synthesized via a simple sol-gel method using low-cost SrCO3, Eu2O3, Mn(CH3COO)(2) center dot 4H(2)O, alpha-Si3N4 and C8H20O4Si (TEOS) as the starting materials. Their luminescence properties, quantum yield, and thermal stability were investigated in comparison with the single Eu2+ doped samples. The green emission intensity of Eu2+ ions is greatly enhanced by introducing Mn2+ ions into SrSi2O2N2:Eu2+ due to the coexcitation and energy transfer between Mn2+ and Eu2+. The energy transfer probability from Mn2+ to Eu2+ depends strongly on the Mn2+ concentration, which is maximized at 2.0 mol%. Mn2+. Simultaneously, quantum efficiency and thermal stability in SrSi2-O2N2:0.03Eu(2+), 0.02Mn(2+) is dramatically improved. All these excellent optical properties indicate that SrSi2O2N2:Eu2+, Mn2+ synthesized in the present work is a promising green-emitting phosphor for white-light emitting diodes with near-UV LED chips. (C) 2013 Elsevier B.V. All rights reserved.