DC electroluminescence in novel n-p Si/ZnS:Mn heterostructures

The behavior of a novel n
⁺
-p Si/ZnS : Mn/ITO light-emitting structure capable of limiting the device current during luminescence is described. In contrast with the very strong dependence of current on voltage observed during luminescence in conventional thin-film ZnS electroluminescent structures, the present structure exhibits a pronounced "knee" or reduction in the rate of growth of current with voltage, which coincides with the onset of electroluminescence. Typically, a decay in brightness of < 5 percent is observed after twelve-hours continuous operation when operating at ∼ 15 ft. L using 0.3-percent duty cycle, 20-µs wide dc pulses.