Temperature dependence of characteristics of characteristics of SrS : Cu(Ag) thin-film electroluminescent devices beyond room temperature

摘要

The temperature (T) dependence of some characteristics of electroluminescence (EL) and photoluminescence (PL) of SrS : Cu(Ag) thin-film electroluminescent devices made by sputtering and atomic layer epitaxy (ALE) techniques has been studied in the range of 20-50℃. The emission spectra do not change markedly, but the PL intensity and EL luminance decrease with the increase of T. However, the former changes much less than the latter. The decrease of luminance (L) is accompanied by a shift of the whole L(U) dependence to higher voltage (U) and a change of the transferred charge (Q). At low voltage (U)Q increases with temperature, but at U higher than the threshold voltage it decreases when the T is increased. The temperature effect depends upon the deposition technique and the composition of the films. It is also somewhat affected by driving conditions (the amplitude, frequency, and width of voltage pulses). Physical causes of observed temperature behavior of the characteristics are discussed.