This experiment was written by Arthur B. Ellis and Lynn Hunsberger, Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706 and George C Lisensky, Department of Chemistry, Beloit College, Beloit, WI 53511. Adapted with permission from Teaching General Chemistry: A Materials Science Companion. © 1993 American Chemical Society. Adapted by S.Michael Condren, Department of Chemistry, Christian Brothers University, Memphis, TN 38104 for measurements with National Instruments' LabVIEW and Educational Laboratory Virtual Instrumentation Suite (NI ELVIS).
In this experiment you will relate observed properties such as the color, wavelength and energy of light, and excitation voltage for a series of compound semiconductors to composition and periodic trends. In addition, you will observe how electrical resistance of a metal changes with temperature and how electrical resistance of a semiconductor changes under illumination. A key objective of this experiment is to relate the solid-state structure to physical properties of these materials.
Procedure | Wear eye protection |
Thermal gloves recommended |
Caution: liquid nitrogen is extremely cold. Do NOT allow it to come into contact with skin or clothing, as severe frostbite may result. |
LED Parts Box
Plano Utility Box
WalMart, #2-3500, $1.89 ea.
Diffraction Grating, Flinn C-Spectra
Flinn Scientific, #AP1714, $14.95 per 8" x 10" sheet.
Battery, 9 Volt
Red Super Bright Water Clear T-1 3/4 LED
Mouser Electronics, #512-MV8112, $0.20 ea in lots of 100.
Orange Super Bright Water Clear T-1 3/4 LED
Mouser Electronics, #512-MV8713, $0.38 ea in lots of 100.
Yellow Super Bright Water Clear T-1 3/4 LED
Mouser Electronics, #512-MV8313, $0.38 ea in lots of 100.
Green Super Bright Water Clear T-1 3/4 LED
Mouser Electronics, #512-MV8412, $0.29 ea in lots of 100.
Blue Water Clear T-1 3/4 LED
Mouser Electronics, #606-CMD383UBC/H2, $2.52 ea.
White Water Clear T-1 3/4 LED
Mouser Electronics, #606-CMD333UWC, $3.02 ea.
Economy Encapsulated RF Choke
Mouser Electronics, #43LJ415, $1.18 ea.
CdS Photocell
Jameco Electronics, #202403, $1.49 ea.
1.0 kΩ Battery Clip Circuit, (see below)
1.0 MΩ Battery Clip Circuit, (see below)
Battery Clip Circuits (one with 1.0 kΩ resistor and one with 1.0 MΩ resistor)
Battery Clip, Molded, 6 inch Leads
Mouser Electronics, #123-7016, $0.83 ea.
1.0 kΩ 1/4W Carbon Film Resistor
Mouser Electronics, #291-1K, $0.009 ea in lots of 200.
1.0 MΩ 1/4W Carbon Film Resistor
Mouser Electronics, #291-1M, $0.009 ea in lots of 200.
SIP Break-A-Way Socket, 10 Pin Strip (break off in pair)
Mouser Electronics, #506-510-AG91D, $2.00 ea.
Heat Shrink Tubing
Radio Shack, #278-1627, $2.39 pk.
Other Materials
Liquid Nitrogen
Polystyrene Coffee Cup
Multimeter, Model 26833-00
Cole Parmer, #EW-26833-00, $68.25 ea.
Alligator Clip Adapters
Radio Shack, #270-354, $2.99 pr.