Graduate Thesis Or Dissertation
 

An n-sheet, state-space ACTFEL device model

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/kk91fp15t

Descriptions

Attribute NameValues
Creator
Abstract
  • The objective of the research presented in this thesis is to develop, implement, and demonstrate the utility of an n-sheet, state-space alternating-current thin-film electroluminescent (ACTFEL) device model. In this model, the phosphor layer is discretized into n + 1 layers, with band-to-band impact ionization, space charge creation/ annihilation, and luminescent impurity excitation/do-excitation occurring only at n sheets between the n + 1 layers. The state-space technique is a structured approach in which the ACTFEL device physics implementation is separated from the ACTFEL measurement circuit electrical response, resulting in a set of coupled, first-order differential equations which are numerically evaluated. The device physics implementation begins with electron injection from phosphor/insulator interfaces and band-to-band impact ionization. Phosphor layer space charge generation via band-to-band impact ionization and subsequent hole trapping, trap-to-band impact ionization, and shallow donor trap emission are then added to the model. Finally, impact excitation and radiative relaxation are added to the model to account for ACTFEL device optical properties. The utility of the n-sheet, state-space ACTFEL device model is demonstrated in simulations which verify hypotheses regarding ACTFEL device measured characteristics. The role of phosphor layer hole trapping and subsequent thermionic emission in SrS:Cu ACTFEL device EL thermal quenching is verified via simulation. Leaky ACTFEL device insulators are shown to produce high luminance but low efficiency. A novel space charge estimation technique using a single transferred charge curve is presented and verified via simulation. Hole trapping and trap-to-band impact ionization are shown to produce realistic overshoot in C-V curves, and each results in a different phosphor layer space charge distribution. DC coupling of the sense capacitor used in the measurement circuit to the applied voltage source is required for the generation of ACTFEL device electrical offset, as verified by simulation. Shallow donors are identified as a probable SrS:Ce ACTFEL device leakage charge mechanism. A field-independent emission rate time constant model is shown to yield realistic ZnS:Mn ACTFEL device leakage charge trends.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome, 8-bit Grayscale) using ScandAll PRO 1.8.1 on a Fi-6770A in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details HittJohnC2001.pdf 2017-08-08 Public Download