[ foh-toh-ahy-uh-nuh-zey-shuh n ]
/ ˌfoʊ toʊˌaɪ ə nəˈzeɪ ʃən /
the phenomenon in which the absorption of electromagnetic radiation by an atom in a gas induces the atom to emit a bound electron and thereby become ionized.
Origin of photoionization
1910–15; photo- + ionization
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019