The accomplishments presented in this thesis are the development of three models
for simulation of space charge generation in the phosphor layer of alternating current
thin-film electroluminescent (ACTFEL) devices and the results from simulation
of these models. First, a single sheet charge model is developed and simulated.
The single sheet charge model is a model that simplifies the problem of modeling an
arbitrary distribution of space charge across the phosphor layer by lumping all of the
space charge into a sheet of charge at a specified location in the phosphor layer. In
this model and all subsequent models, space charge creation is assumed to occur by
field emission from bulk traps or by impact ionization of deep-level traps. A fairly
exhaustive parametric variation study of the single sheet charge model is performed
and the results are presented and discussed. The results show space charge effects
that are quite dependent on several parameters such as the number of bulk traps in
the phosphor layer, the location of the sheet of charge, the capture efficiency for space
charge annihilation, and the characteristic field for impact ionization of the deep-level
traps. The second model considered is a logical extension of the single sheet charge
model, the two sheet charge model, which models the space charge distribution as
two sheets of charge rather than one. This model has potential application in the
simulation of ACTFEL devices which exhibit large and/or symmetrical space charge
effects. The final model developed is an equivalent circuit/SPICE model of the single
sheet charge model. Actually, two models are developed, one for space charge
creation by field emission and one for impact ionization of deep-levels. Two SPICE
models are required because of functional differences in the dependencies of space
charge creation. The results of a simulation showing overshoot generated by SPICE
are given for the field emission equivalent circuit. / Graduation date: 1996
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/34670 |
| Date | 11 August 1995 |
| Creators | Keir, Paul D. |
| Contributors | Wager, John F. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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