Lighting the City: Photoemitters

Photoemittersare solid materials that exhibit the photoemission of electrons when

illuminated. Photoemission is the ejection of electrons from the surface of said material due to incident electromagnetic radiation. Examples of photoemitters are lightbulbs, LCD lights, basically anything that illuminates. In light bulbs for example, when a current of electrons pass through a thin metal filament, the light bulb emits the energy as light. So, the main source of light we experience comes from heat energy. These are known as luminescence, and there are three types, including bioluminescence, chemiluminescence, and triboluminescence.

The luminescence that would be most eco-friendly and economically beneficial would be bioluminescence. Bioluminescence is the production and emission of light by a living organism (such as fireflies!) The animals that have bioluminescence contain two chemicals called luciferin, which is a pigment, and luciferase which is an enzyme. When luciferin reacts with oxygen it creates light, and the luciferase acts as a catalyst to speed up the reaction. Now there are two possibilities to harvest the light that these creatures produce. One would just to have a concentrated area of lightning bugs, for example, and have that light up the area. The lightning bugs are renewable, since they reproduce, and don't cost anything to harvest, since they do it naturally. However, they would need to be fed, but this would be the only cost-worthy part of the process. Another possibility would be figuring out how to extract/create luciferin, and how to control it in a system where it isn't constantly reacting with oxygen. To have a switch that would change the environment of the luciferin from a air-tight space, to a space filled with oxygen and then back again would make the most use out of luciferin. Because our atmosphere is filled with oxygen, luciferin would constantly react, thus providing light at all periods during the day, which is unnecessary, demonstrating the importance of having it in a controlled environment.

To advertise the effectiveness of bioluminescence, I would set up a New Years Eve show that involved a light show, with the use of just bioluminescence. First of all, many people would be watching from around the world, and people would be able to experience at first hand the effectiveness of bioluminescence. Thus, people would be willing to invest in changing their lighting source all around the world, which in the long run would help the situation of global warming, by reducing the emission of greenhouse gases that power our light sources today.