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Contents 1 LED color change in Liquid Nitrogen 1.1 A brief Introduction 1.2 Demonstration 1.3 Image Gallery 1.4 References

LED color change in Liquid Nitrogen

A brief Introduction

This demonstrtion show the change in the properties of the LED. Light emmitting diodes produce light when electrons recombines with holes in the junction. The color emmitted by an LED depends on the band gap. Dipping an LED in the liquid nitrogen changes the bandgap properties. This demonstrates intrinsic changes in semiconductor properties.

need volunteer

Demonstration

With an LED on, dip into liquid nitrogen. Watch color change. It works best with Yellow LED, although any LED will change color.

Image Gallery

References

1. http://en.wikipedia.org/wiki/Led - In wikipedia
2. http://www.owlnet.rice.edu/~chem152/lab152/bandtheory/
3. https://eee.uci.edu/programs/gchem/06MANLED.pdf
4. http://mvh.sr.unh.edu/software/software.htm Mvh software to analyze color

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