fotoelektronteooria

Fotoelektronteooria, also known as the photoelectric effect theory, is a fundamental concept in quantum mechanics that explains the emission of electrons from a material when light shines on it. Albert Einstein was awarded the Nobel Prize in Physics in 1921 for his explanation of this phenomenon.

The theory posits that light is not a continuous wave but rather consists of discrete packets of energy called photons. The energy of each photon is directly proportional to the frequency of the light, a relationship described by Planck's equation E=hf, where E is energy, h is Planck's constant, and f is frequency. When light strikes a material, individual photons can transfer their energy to electrons within the material.

If a photon's energy is sufficient to overcome the binding energy of an electron to the material (known as the work function), the electron can be ejected. This ejected electron is called a photoelectron. The minimum energy required to eject an electron is the work function, which is a characteristic property of the specific material. Any energy from the photon exceeding the work function is converted into the kinetic energy of the emitted photoelectron.

A key observation explained by fotoelektronteooria is that the emission of photoelectrons is instantaneous, regardless of the light's intensity, as long as the frequency is above the threshold required for emission. Below this threshold frequency, no electrons are emitted, no matter how intense the light. This particle-like nature of light, explained by Einstein's theory, was a crucial step in the development of quantum mechanics and has applications in fields such as photovoltaics and photomultipliers.