Course E. Electron Field Emitters: Theories, Characterization and Applications.

RJN - Robert J. Nemanich North Carolina State University

JLD - Jim L. Davidson, Vanderbilt University

WPK – Weng Poo Kang, Vanderbilt

I. Theories and Characterization (RJN)

Introduction

Applications motivation: flat panel display, microwave cathodes, other cathodes

Carbon Materials – diamond, CVD diamond, DLC, nanocrystalline diamond, graphite, nanotubes.

Electron Affinity and Work Function of Carbon Materials

Definitions and surface dipole

Measurement

UPS, SEE, Kelvin Probe etc.

Controlling electron affinity

Surface adsorbates and overlayers

Other wide band gap materials

Schottky Barriers and Band Bending

Schottky barriers and surface preparation

Surface Fermi level and band bending

Electron emission fundamentals

Thermionic emission

Space charge limited current

Field Emission

Fowler Nordheim analysis

Thermionic Field emission

Field enhancement (vs. NEA emission)

Triple junction effects

Measurement of field emission from flat surfaces

Moving and fixed anode (threshold field)

Transparent Cathode (emitting site density)

FEEM and PEEM

Issues: field application, damage, shorts and other artifacts

Review of results of field emission

p-type diamond, N-doped diamond

Defective diamond

DLC

Needles and flat surfaces

Nanocrystalline diamond

Nanotubes

Other wide band gap materials

II. Examples of Fabricated Structures, Device Concepts and Applications (JLD)

Introduction

Device Configurations

Tipped cathodes/vertical emitters

Metal, Si, other

Lateral Devices

Nanotube Emitters

Stochastic vs. Lithographic

Gated Microstructures/Displays

Applications (besides displays)

Operating triode (transistor)

MEMS / conventional (pressure, accel., etc.)

MEMS / EM

Electric/ion propulsion (space)

Power Diode

Solar Conversion

Other

III. Developing a Field Emission Device – A Case Study (WPK)

Background

Material Selection

Process Approaches

Process Iterations

Third Terminal (Gate) Derivation

Parametric Effects

Electronic Performance

Specific and Generic Issues for FEDs