Photoluminescence is light emission following absorption of incident photons. The excitation first puts matter into excited states; subsequent relaxation can emit at a different wavelength. Fluorescence and phosphorescence are distinct forms whose timing and transition mechanisms differ.
An excitation source, sample, rejection filter and spectrometer form a simple experiment. Place collection optics away from the directly transmitted beam and suppress excitation light before measuring the emission optical spectrum. Recording an empty holder or solvent blank helps identify background. Emission intensity alone does not determine absorption or quantum yield, because collection geometry and nonradiative relaxation also affect the signal.
Photoluminescence is the process by which a material absorbs photons (light) and then re-emits them. This phenomenon is a form of photonic emission that occurs when a substance absorbs energy, usually from ultraviolet (UV) or visible light, and subsequently emits light of a longer wavelength.
New to topics? Read the docs here!