1. The process by which a photon of light energy raises an electron from a lower energy state to a higher energy state in an atom or molecule.
Usage: technical; physics; chemistry

Examples

• Photoexcitation of electrons in a semiconductor is the basis for solar cell operation.
• The laser's ultraviolet light caused photoexcitation of the dye molecules.
• Photoexcitation can lead to fluorescence when the excited electron returns to its ground state.
• In photosynthesis, photoexcitation of chlorophyll molecules initiates the light-dependent reactions.
• The efficiency of photoexcitation depends on the wavelength of the incident light.