Reference Terms
from Wikipedia, the free encyclopedia
Photoelectric effect
The photoelectric effect is the emission of electrons from matter upon the absorption of electromagnetic radiation, such as ultraviolet radiation or x-rays. Upon exposing a metallic surface to electromagnetic radiation that is above the threshold frequency or threshold wavelength (which is specific to the type of surface and material), the photons are absorbed and current is produced. No electrons are emitted for radiation with a frequency below that of the threshold, as the electrons are unable to gain sufficient energy to overcome the electrostatic barrier presented by the termination of the crystalline surface.
By conservation of energy, the energy of the photon is absorbed by the electron and, if sufficient, the electron can escape from the material with a finite kinetic energy. A single photon can only eject a single electron, as the energy of one photon may only be absorbed by one electron. The electrons that are emitted are often termed photoelectrons.
Related Stories
1
2
Matter & Energy News
May 11, 2026
May 10, 2026 A team at the University of Hong Kong has developed a new “super steel” that can survive the harsh conditions needed to make green hydrogen from seawater. The material uses an unexpected double-protection mechanism that resists corrosion far ...
May 9, 2026 Scientists have taken a major step toward ultra-secure quantum communication by demonstrating a remarkably stable quantum encryption system that worked across more than 120 kilometers of optical fiber. Using tiny semiconductor quantum dots that emit ...
May 9, 2026 A major obstacle may be standing in the way of the next generation of ultra-tiny computer chips. Researchers discovered that many promising 2D materials lose their advantages because an invisible atomic-scale gap forms when they are combined with ...
May 6, 2026 Cumberland, B.C. is reimagining its coal mining past as a clean energy opportunity. Water trapped in abandoned mine tunnels could be used in a geothermal system to heat and cool buildings efficiently and with minimal emissions. The project could ...
May 6, 2026 A powerful new electromagnetic thruster has taken a major step forward after a successful high-energy test at NASA’s Jet Propulsion Laboratory. Fueled by lithium vapor and driven by intense magnetic forces, the experimental engine reached ...
May 5, 2026 Creating complex molecules usually requires years of experience and countless decisions, but a new AI system is changing that. Synthegy lets chemists guide synthesis and reaction planning using simple language, while powerful algorithms generate and ...
May 5, 2026 A strange kind of matter that “ticks” forever without energy input has just taken a major leap toward real-world use. Known as a time crystal, this quantum system repeats its motion ...
May 5, 2026 Researchers at Stanford have developed a compact optical amplifier that dramatically boosts light signals using very little power. By recycling energy inside a looping resonator, the device achieves strong amplification with minimal noise and wide ...
May 4, 2026 A new quantum physics study reveals that simply changing a magnetic field over time can unlock entirely new forms of matter that don’t exist under normal conditions. By carefully “driving” materials with timed magnetic shifts, researchers ...
May 4, 2026 Scientists are using sunlight to turn plastic waste into clean fuels like hydrogen, offering a breakthrough solution to both pollution and energy challenges. While still in development, the approach could transform trash into a valuable resource for ...
May 4, 2026 For decades, relaxor ferroelectrics have powered everything from medical ultrasounds to sonar systems, yet their inner atomic structure remained a mystery—until now. Researchers have finally mapped ...
May 1, 2026 In a striking glimpse into extreme physics, scientists have captured the split-second chaos that unfolds when powerful laser flashes blast matter into a superheated plasma. By combining two cutting-edge lasers, researchers were able to track how ...
Latest Headlines
updated 12:56 pm ET
May 11, 2026 Scientists have pulled off a mind-bending quantum experiment that sounds almost impossible: they showed that tiny metal particles made of thousands ...
May 9, 2026 Physicists may have just cracked open a hidden side of the quantum world. For decades, every known particle was thought to belong to one of two categories — bosons or fermions — but researchers ...
May 8, 2026 Scientists may have uncovered a surprising secret behind why life exists at all. A new study suggests that the Universe’s fundamental constants — ...
May 6, 2026 In a major breakthrough, scientists have experimentally confirmed a universal growth law in two dimensions using a quantum system of fleeting light–matter particles. The finding strengthens the ...
May 3, 2026 Physicists are rethinking one of quantum mechanics’ biggest puzzles: how fuzzy possibilities become definite reality. New research suggests that spontaneous “collapse” processes—possibly ...
May 1, 2026 Scientists have created a powerful new way to control quantum systems, achieving the first-ever demonstration of quadsqueezing—an elusive ...
May 1, 2026 A team at King’s College London has created a powerful new aluminum compound capable of doing the work of expensive rare metals. Its unique triangular structure gives it remarkable stability and ...
Apr. 30, 2026 Scientists have pulled off a first: teleporting a photon’s state between two separate quantum dots. This was done over a 270-meter open-air link, proving quantum information can travel between ...
Apr. 28, 2026 Quantum physics once shocked scientists by revealing that particles can behave like waves—and now, that strange behavior has been pushed even ...
Apr. 28, 2026 A massive cosmic milestone has just been reached: scientists have completed the largest high-resolution 3D map of the universe ever created. Built using data from over 47 million galaxies and ...