photoelectric effect


: the emission of free electrons from a metal surface when light strikes it

Examples of photoelectric effect in a Sentence

Recent Examples on the Web It was eventually disproved—thanks to the famous Michelson-Morley experiment in 1887 and Albert Einstein's development of special relativity and his paper on the photoelectric effect in 1905 (his annus mirabilis). Jennifer Ouellette, Ars Technica, 4 Feb. 2023 There are more fundamental possibilities, too, such as more detailed explorations of Einstein’s famed photoelectric effect, in which a photon impinges on metal, causing the metal to emit an electron. Daniel Garisto, Scientific American, 3 Oct. 2023 In his first paper, Einstein applied German physicist Max Planck’s quantum theory to light to explain the photoelectric effect. USA TODAY, 31 May 2023 Hertz’s discovery in 1887 of the photoelectric effect and the longstanding observation that Mercury’s orbit precesses around the Sun faster than predicted. The Physics Arxiv Blog, Discover Magazine, 12 Sep. 2022 Two years later, Einstein won the Nobel Prize in Physics, not for general relativity, but for his discovery of the photoelectric effect. Mark Barna, Discover Magazine, 16 Dec. 2022 Other papers that year were on Brownian motion, suggesting the existence of molecules and atoms, and the photoelectric effect, showing that light is made of particles later called photons. Mark Barna, Discover Magazine, 16 Dec. 2022 Albert Einstein explains the photoelectric effect—shining light on certain materials can function to release electrons from the material—and suggests that light itself consists of individual quantum particles or photons. Gil Press, Forbes, 18 May 2021 Albert Einstein proposed a theory of the photoelectric effect in 1905, describing the phenomenon in which electrons can be ejected from atoms after they are hit by light. NBC News, 19 Oct. 2020

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'photoelectric effect.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1892, in the meaning defined above

Time Traveler
The first known use of photoelectric effect was in 1892

Dictionary Entries Near photoelectric effect

Cite this Entry

“Photoelectric effect.” Dictionary, Merriam-Webster, Accessed 17 Jul. 2024.

Kids Definition

photoelectric effect

: the giving off of free electrons from a metal surface when light strikes it

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