All inorganic colloidal quantum dot LEDs
Name
192001982-MIT.pdf
Description
Full printable version
Size
11.88 MB
Format
Adobe PDF
Checksum (MD5)
a41639629e32e4a7a6de0be92053f205
Author(s)
Wood, Vanessa Claire
Advisor(s)
Vladimir Bulović.
Alternative Title
All inorganic colloidal QD light emitting devices
Date Issued
2007
Publisher
Massachusetts Institute of Technology
Abstract
This thesis presents the first colloidal quantum dot light emitting devices (QD-LEDs) with metal oxide charge transport layers. Colloidally synthesized quantum dots (QDs) have shown promise as the active material in optoelectronic devices because of their tunable, narrow band emission. To date, the most efficient QD-LEDs involve a monolayer of closely packed QDs sandwiched between organic charge transport layers. However, these organic materials are subject to degradation due to atmospheric oxygen and water vapor. In contrast, metal-oxide films used in this work are chemically and morphologically stable in air and can withstand numerous organic solvents, which increases the flexibility of device processing. Furthermore, they can sustain higher carrier injection rates needed to realize an electrically pumped colloidal QD laser. This thesis details the characterization techniques, such as Atomic Force Microscopy, photoluminescence spectroscopy, Hall Effect measurements, X-Ray Diffraction, and Ultraviolet Photoelectron Spectroscopy, used to design efficient QD-LEDs. It reviews the steps used to optimize device performance and obtain a transparent device architecture with external quantum efficiency of 0.15% and a peak luminance of 7000 Cd/m2. This manifests a 100-fold improvement in efficiency over any previously reported all inorganic QD-LED structure.
Description
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.
Includes bibliographical references (p. 85-89).
Subjects
Electrical Engineering and Computer Science.
MIT Department
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
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