How does glow-in-the-dark work? Like many natural phenomena associated with light and color, it’s easy to forget that there’s science happening behind the scenes—not magic! In fact, learning about glow-in-the-dark science only makes you appreciate how magical our universe really is. So, how do glow-in-the-dark stickers work? Get the facts here!
What Is Phosphorescence?
Phosphorescence is the process that causes stickers and other items to glow. Phosphors are solid materials that cause phosphorescence to occur. The word phosphors is derived from the Greek word phōsphoros, which means light bringer. Phosphors can be found in glow-in-the-dark materials, as well as fluorescent lights, TV screens, and computer monitors.
So, how does glow-in-the-dark work? In order to understand phosphorescence, you need to first understand how phosphors work. Phosphors are photoluminescent, which means that they can be energized by light.
Phosphors have three distinct characteristics—the type of energy they require to become energized, the color of light they emit when energized, and how long they emit that light after being energized (persistence). Phosphors that glow in the dark must be able to be energized by visible or ultraviolet light, and they must have a long persistence.
In contrast, the phosphors in fluorescent materials, for example, have an extremely short persistence. They stop glowing within nanoseconds of their energy source being shut off. How does glow-in-the-dark work? To put it simply, the phosphors absorb light as energy and then release that energy slowly over time. Let’s dive deeper!
Glow-in-the-Dark Science
Now that you have a fundamental understanding of what phosphorescence and phosphors are, let’s go a little more in-depth. How do glow-in-the-dark stickers work? Here’s what’s happening at an atomic level.
Phosphors Absorb Light as Energy
If you’ve ever used glow-in-the-dark stickers, you know that they need to be “charged” before they start emitting light. The charging process simply means turning on a normal light or exposing them to sunlight for a few minutes.
How does glow-in-the-dark work during the charging process? When you expose phosphors that have those specific characteristics mentioned above to visible or ultraviolet wavelengths, they absorb the light, which excites the phosphors’ electrons. As the electrons are exposed to light for extended periods of time, they store the energy and move to increasingly higher energy levels.
Phosphors Release Energy as Light
When you stop charging the phosphors (turn the lights off), they slowly drop back down to normal energy levels. That surplus of energy that they just stored is released little by little, which is what causes the glowing effect. Once the phosphors reach normal energy levels, they stop glowing.
How does glow-in-the-dark work compared to fluorescence? It’s essentially the same process, but fluorescent phosphors release the stored light energy incredibly rapidly—so fast you can switch the “glow” on and off with the flick of a switch.
Materials With Glow-in-the-Dark Phosphors
Now that you’re familiar with the basics of glow-in-the-dark science, let’s talk about the specific materials used in stickers and other products that glow. Remember: the phosphors need to have those characteristics—the ability to be charged by normal visible light and release the energy slowly. The materials with phosphors that check both boxes are zinc sulfide and strontium aluminate. How does glow-in-the-dark work without those materials? Well, it doesn’t!
Science Experiments to Try
How do glow-in-the-dark stickers work as classroom learning aids? You can try charging them with different light sources and for different amounts of time, and then compare the stickers’ brightness and persistence.
For example, you could charge the stickers for five minutes with an ordinary lamp, and then time how bright the stickers get and how long it takes until they stop glowing. Then, you could charge them for five minutes in direct sunlight to see if they glow brighter and/or longer.
You might be wondering, how does glow-in-the-dark work if you never turn off the lights and just keep charging? Well, once the phosphors reach the limit of how energized they can get, they won’t store any more energy. In other words, they do max out eventually. You can perform glow-in-the-dark science experiments to try to pinpoint how long it takes to reach the full charge.
Let’s say you charge the stickers for 5 minutes and then they glow for one hour. Next, you charge them for 10 minutes, but they still only glow for one hour. That means that the extra five minutes of charging didn’t excite the phosphors anymore because they already reached their peak energy levels. Now you can ask yourself, how does glow-in-the-dark work if I charge the stickers for less than five minutes?
So, you charge the stickers for one minute this time. Did the results change? If they didn’t glow for as long as before, that means their maximum energy levels can be achieved within between one and five minutes. Now, try two minutes of charging. Then, three. Keep performing the experiment until you pinpoint the approximate time they stop charging.
Order Glow-in-the-Dark Stickers Today
Whether you’re interested in educational science supplies or fun decorations, our glow-in-the-dark stickers are sure to please! How does glow-in-the-dark work? Order our Nostalgia Glow and Desert Glow sticker sheets to experience the fascinating science first-hand.
We hope this guide to glow-in-the-dark science is helpful as you explore the captivating world of phosphorescence and the study of light and color as a whole. Check our science blog for more fun lessons and experiment ideas. Order your glow-in-the-dark stickers now!
