Green emitting alternating current thin film electroluminescent devices were fabricated on glass substrates in the conventional MISIM structure using ZnGa2O4:Mn as the active layer. The devices were fabricated varying the deposition time of the active/phosphor layer at two different substrate temperatures, 500 and 600 degrees C. The active layer and top dielectric layer were deposited using rf magnetron sputtering technique. All devices gave an emission in the green region of the visible spectrum even without any post deposition annealing. The EL emission could be de-convoluted into two/three peaks attributed to the T-4(1)-(6)A(1) transition of Mn2+ centers at various sites in the host lattice. The intensity of the 502 nm EL emission was found to increase with active layer thickness. The luminance versus voltage plots exhibit an increase in threshold voltage with increase in phosphor layer thickness. The purity of the EL emissions is gauged using CIE coordinates that are found to lie in the green region of the chromaticity diagram. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3604755] All rights reserved.