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Luminescence

This slide show was created by Vivian Ezeh, Colgate University (vezeh@colgate.edu) and posted on VIPEr (www.ionicviper.org) on Aug 18, 2014. This work is licensed under the Creative Commons Attribution Non-commercial Share Alike License. To view a copy of this license visit http://creativecommons.org/about/license/.

Luminescence

The emission of light from the excited state of a substance

Application of Luminescence

Medical Diagnostics, Flow cytometry, Forensics, Phosphors, Glow toys, Chemical reactions etc.

http://www.shsu.edu/chm_tgc/chemilumdir/JABLONSKI.html

Insert Jablonski diagram from

Fluorescence – Quantum Dots

Nano-sized semiconductors (Q-dots) exhibit intense fluorescence properties. Examples include CdS, CdSe, InP, InAs, ZnS, PbSe.

The emission wavelength of Qdots depends on the size of the particle. The larger the size the longer the emission wavelength.

Color photographs of CdSe nanoparticles illuminated with a long-wave UV lamp

Insert figure 20.1 from:Lakowicz, J. R., Principle of Fluorescence Spectroscopy. Kluwer Academic/Plenum: 2006; p 676

Phosphorescence – Alkaline earth aluminates (MAl2O4, M = Ca, Ba, Sr) doped with Rare earth ions

SrAl2O4:Eu2+, Dy3+

Exposed to lightSrAl2O4:Eu2+, Dy3+

Glowing in the dark (λem = 520 nm)

Insert Fig 1 from Solid State Sciences, 2007, 9, 608

"Phosphorescent pigments" by FK1954 - Own work. Licensed under Public domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Phosphorescent_pigments.jpg#mediaviewer/File:Phosphorescent_pigments.jpg

Chemiluminescence – Ru(bipy)32+

N N

N

N

NN

Ru

2+

N N

N

N

NN

Ru

3+

N N

N

N

NN

Ru

2+ *

hv (610 nm)

Oxidation

Add Analyte

Triboluminescence – [Ph3PCH3]2MnBr4

P

2

Mn

Br

Br Br

Br

Insert Figure 2 from Inorg. Chem. 2014, 53, 6054

Grind or exposure to aprotic solvents P

2

Mn

Br

Br Br

Br

Faint green Bright green