Date : Friday, February 8, 2002
Time : 3:00 PM
Location: Willet Science Center Room 101
Professor Dale Moore
Department of Chemistry
"The Unusually Intense
Photoluminescence of Semiconductor Quantum Dots"
Extremely small crystallites of semiconductors, such as cadmium sulfide (CdS),
can be prepared by precipitation reaction in a product-size-limiting medium.
If the crystallite diameter is kept below about 10.0 nm, then the
crystallites formed behave as quantum dots.
The dimensions of quantum dots are so small that excited electrons (and
holes) are effectively modeled with the particle-in-a-box
(PIB) – in other words, they are spatially confined.
This confinement increases the energy required to electronically excite a
quantum dot and makes the optical-electronic properties of quantum dots size
dependent. Among the most unusual
properties of quantum dots is their intense photoluminescence.
This seminar will be a brief introduction to semiconductor
photoluminescence, the particular nature of quantum dots, and one theory to
quantify the unusually intense quantum dot photoluminescence
Please join us for light refreshments at 2:45. We hope to see you there!