JCE Online Journal of Chemical EducationDivision of Chemical Education, American Chemical SocietyAmerican Chemical Society
 | Subscriptions  | Software Orders  | Support  | Contributors  | Advertisers  | 

JCE Print
   Current Issue
 Previous Issues
 Supplements
 Search JCE Index

JCE Digital Library
   ChemInfo
 DigiDemos
 Featured Molecules
 LivTexts
 LrnCom
 QBank
 SymMath
 WebWare

JCE Software
   Latest Releases
 Software & Video
 Downloads
 Support

Only@JCE Online
   JCE Online Store
 JCE HS CLIC
 JCE Discussion Forums
   Biographical Snapshots
 ChemEd Resource Shelf
 Featured Molecules
 Hal's Picks
 Project Chemlab
 Reviewed WWW Sites
 "Web-Ed" Articles

About JCE
   Features
 Publications
 Operations
 Outreach
 Contact Us


  Home > JCE Print > Journal of Chemical Education > Issues > 1996  > November  >
In the Laboratory
Experiments with Glow-in-the-Dark Toys: Kinetics of Doped ZnS Phosphorescence
George C. Lisensky, Manish N. Patel, and Megan L. Reich
Beloit College, Beloit, WI 53511
Cover
November 1996
Vol. 73 No. 11
p. 1048
Abstract
Many semiconductors exhibit the property of phosphorescence, the phenomenon whereby a material excited by visible or ultraviolet radiation glows (i.e., emits visible light) for a substantial time after the excitation source has been removed. One phosphorescent semiconductor commonly used in glow-in-the dark toys and emergency signs is copper-doped zinc sulfide (ZnS:Cu), a material that produces a yellow-green glow. The study of this light emission is a suitable introduction to kinetics and to semiconductors. Intensity data were recorded for a Glow-Yo yo-yo, an Amazing Glow Ball, Hanovia P-1000 pigment, and Glo-Vinyl Tape by spectrofluorophotometer and also by using a CdS photocell and ohmmeter. The emission of the ZnS semiconductor is not across the band gap, but involves interband traps associated with the Cu doping material. The phosphorescence decay of ZnS:Cu fits a second order equation, consistent with recombination of relatively equal populations of holes and electrons (n ~ p). Arrhenius data show the delocalized electrons in the conduction band must overcome a small but measurable activation energy of about 15 kJ/mol to fall back to the localized copper-site holes for the recombination that produces phosphorescence.
More Information
*  Citation
 Lisensky, George C.; Patel, Manish N.; Reich, Megan L. J. Chem. Educ. 1996 73 1048.
*  Keywords
 Physical Chemistry
*  History
 Created:
Last Updated:		 August 5, 1999
February 21, 2006
<< Previous Article Table of Contents Next Article >>
  Home > JCE Print > Journal of Chemical Education > Issues > 1996 > November > Page 1048


Subscriptions
 Subscription Info
 Order Forms

JCE HS CLIC

Our Secondary School editors work hard to distill all the JCE materials to produce a fraction of particular interest to high school teachers. We call it CLIC.
 JCE HS CLIC

Contributions Welcome
JCE welcomes your submission
 Contributors' Corner

Advertisers
In recent years we have worked hard to better match our advertisers with our readers. When shopping for chemistry education materials, visit our advertisers' WWW sites first.
 Recent Advertisers

Be An Ambassador
Take JCE along on your outreach missions. Copies of the Journal, guest access to JCE Online, our publications catalog, and more are available for your participants.
 Outreach with JCE

Comments to
jceonline@chem.wisc.edu		 Copyright © Division of Chemical Education, Inc., American Chemical Society.
All rights reserved.