Effects of UV Light

When you explored the properties of glow-in-the-dark objects, you may have found that ultraviolet light is also effective in causing phosphorescence. With the software create an energy band diagram of the glow-in-the-dark toothbrush that utilizes UV light (3.5 eV). Manipulate the variables until you can explain

 

• how this energy band diagram is similar to and different from the energy band diagram used to describe the glow-in-the-dark toothbrush when it was exposed to visible light, and
• how the resulting energy band diagram is consistent with conservation of energy.

 

In your explorations you probably noticed phosphorescent objects do not glow after being exposed to red light. Use this information, the energy level model and your knowledge of energies of the colors of light to place a limit on the energy between the valence and conduction bands. Then sketch all three bands and label the relative energies. Justify the energies with your observations.