Photoluminescent materials are substances that can absorb light and then re-emit it. When these materials are exposed to a light source, they store energy and release it slowly, producing a glow. This phenomenon is commonly seen in items like glow-in-the-dark stickers and safety signs, which help improve visibility in low-light conditions. The process of photoluminescence involves two main steps: absorption and emission. First, the material absorbs photons from a light source, exciting its electrons. Then, as the electrons return to their original state, they release energy in the form of light. Common examples of photoluminescent materials include zinc sulfide and strontium aluminate.