Characterization of the electrical properties of SrS:Ce thin‐film electroluminescent devices

Abstract

Abstract— The electrical properties of SrS:Ce thin‐film electroluminescent (TFEL) devices were studied. Photo‐irradiation effects on capacitance‐voltage and charge‐voltage characteristics of SrS:Ce TFEL devices were measured and compared with those of ZnS: Mn devices. For the SrS:Ce device, the polarization charge due to the positive space charge was estimated to be 0.94 μC/cm2. This polarization charge was remarkably reduced by photo‐irradiation. For the ZnS: Mn TFEL device, the polarization charge due to the positive space charge was 0.66 μC/cm2. However, the reduction of the polarization charge by photo‐irradiation was small compared to that of the SrS:Ce device. The unique electrical and optical characteristics observed in the SrS:Ce TFEL devices such as relaxation of phosphor field and leading‐ and trailing‐edge emissions are considered as functions of the large amount of space charge and also due to the electron emission from electron traps and electron recapture by the traps.