Abstract:
Offset is observed in the charge–voltage (Q–V) or internal charge–phosphor field (Q–Fp)
characteristics of certain alternating-current thin-film electroluminescent (ACTFEL) devices. This
offset arises from a displacement along the voltage axis of a transient curve measured across a sense
capacitor in the electrical characterization setup. A procedure for adjusting this offset is proposed
that allows ACTFEL devices manifesting offset to be meaningfully analyzed. Two possible sources
of offset are deduced from simulation and are associated with an asymmetry in the interface state
energy depths at the two phosphor–insulator interfaces or with an asymmetry in the location of
space charge generation in the phosphor.
