Heinrich Hertz1857 - 1894

Photoelectric Effect (1)

Discovered in 1887:

Light can lead to the emission of electrons

from metal surfaces. Only the wavelength,

not the intensity of the light matters!

< picture from www.wikipedia.org >

Albert Einstein1879 – 1955

Photoelectric Effect (2)

Nobel Prize for Physics (1921)

for explanation of the Photoelectric Effect:

Light energy is quantized (see Max Planck).

If the energy of a light quantum (photon) is

greater than the work function of a

given material, electrons will be emitted.

< picture from www.wikipedia.org >

Louis Victor Pierre Raymond, 7e Duc de Broglie

(1892 - 1987)

Matter Waves

Nobel Prize for Physics, 1922

< picture from www.wikipedia.org >