Date of Submission

Spring 2012

Academic Program


Project Advisor 1

Matthew Deady

Abstract/Artist's Statement

The goal of this project was to calculate an accurate value of Planck's constant, h, using the principles of how light-emitting diodes work. After a simple working device was built, I made a more substantial apparatus to help Modern Physics students replicate the same experiment in the future. The experiment itself revolves around what is known about diodes, LEDs, and electron energies to compare the threshold voltage of an LED to the energy of the diode's band gap. Measurements of the band gap, and thus the emitted photon energy, for a series of different colored LEDs then provides a measurement for h. In this paper, I will explain the relevant concepts and theory behind diodes and LEDs, take the reader through the procedure, and describe how I came to my conclusions, as well as the difficulties and snags I faced involving the experiment. A description of the actual device to replicate the experiment is included, as well as instructions on how students can use it effectively.

Distribution Options

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Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.