Electroluminescence thermal quenching in SrS : Cu thin-film electroluminescent devices

Electroluminesence (EL) thermal quenching refers a reduction in luminance, concomitant with a reduction in transferred charge, when an alternating-cur rent thin-film electroluminescent (ACTFEL) device is operated at an elevate d temperature. EL thermal quenching is found to be significant in SrS:Cu AC TFEL devices operated above similar to 60-80 degrees C. Maximum transferred charge-maximum applied voltage (Q(max)-V-max) and transferred charge capac itance (i.e., dQ(max)/dV(max) vs V-max) measurements as a function of tempe rature in conjunction with ACTFEL device simulation are employed in order t o establish that EL thermal quenching arises from a thermally activated ann ihilation of positive space charge and a corresponding increase in the thre shold voltage. (C) 2000 American Institute of Physics. [S0003-6951(00)02902 -8].