Using Color to Enhance LED Lighting Quality
Vividly colored quantum dots are manufactured for use in technology such as for TVs, monitors and cell phone backgrounds.Copyright 2012 Antipoff, Wikimedia Commons, GNU Free Documentation License https://commons.wikimedia.org/wiki/File:Quantum_Dots_with_emission_maxima_in_a_10-nm_step_are_being_produced_at_PlasmaChem_in_a_kg_scale.jpg
Students take what they know about materials, optical properties and electrons to the next level—to see how semiconductors can be used to augment light. First, they learn how light-emitting diodes (LEDs) work, which helps them to think critically about a real-world problem they are asked to solve later in the activity as if they are practicing engineers. The challenge: To design an improved LED headlight that lights the roadway without distracting oncoming drivers and passengers with the harsh, bright white light seen in many cars today. Students research the problem via an online video, article and interactive simulation, learning all about quantum dots. Then teams use small LED flashlights and pieces of red, blue, yellow and green acetate to independently experiment to come up with a model that has the potential to improve the measured visual quality of bright white LED light—their solutions to the headlight challenge.
We live in a world in which improvement and optimization are continual goals. Engineers are instrumental in evolving the latest cutting-edge technology and are currently working to improve lighting properties by using quantum dots. Quantum dots are semiconductor nanocrystals that glow when stimulated by an external source such as ultraviolet (UV) light. In this activity, students see how quantum dots are used to increase the lighting quality of LEDs. Because of their ability to enhance color brightness and definition, quantum dots are increasingly used in modern day technology. For example, TV manufacturers employ quantum dots to make TVs brighter and improve color quality. Quantum dots eliminate the filtering process used in LED TVs, which lowers the energy use while producing brighter colors. Engineers also utilize quantum dot technology in personal electronics, such as to increase battery life in cell phones.
After this activity, students should be able to:
- Apply their prior knowledge about the periodic table, semi-conductors and wave properties to explain how light-emitting diodes produce light.
- Demonstrate how colors can be used to dim the lighting of LEDs.
- Create a visual representation of various color combinations colors to maximize LED lighting quality.