KINETICS AND AGING IN ATOMIC LAYER EPITAXY ZNS:MN AC THIN-FILM ELECTROLUMINESCENT DEVICES

The kinetics of the aging of atomic layer epitaxy ac thin-film electroluminescent devices was studied. In a first series of experiments, we aged devices at different temperatures from 50 to 190 °C, and measured the steady-state transferred charge versus voltage characteristics. From monitoring Q145 V, the charge transferred at 145 V, we could trace the relationship between Q145 V and the aging time. The aging process was found to be temperature dependent, and we could deduce an activation energy of 0.34 eV. In a second series of experiments, devices were aged 16 h at room temperature and subsequently heat treated at different temperatures from 250 to 450 °C. Monitoring again Q145 V, we found that the devices recover from aging following the relationship −krecot=ln[Q145 V/Q145 V(t=0)], where t is the heat treatment time. The recovery rate constant kreco was found to have an activation energy of 1.3 eV. In a last series of experiments we found the aging rate to be proportional with the transferred charge. P...