Einstein Photoelectric Theory

Einstein's Photoelectric Theory

7.3

Einstein's Photoelectric Theory

	Einstein's Photoelectric Equation
	\(\dfrac{1}{2}mv_{maks}^2 = hf-W\)

	At the threshold frequency \(f_0\), kinetic energy = 0, then
	\(\dfrac{1}{2}mv_{maks}^2=h(f-f_0)\)

	Work function
	The minimum energy required for a photoelectron to be emitted from a metal surface.
	\(W=hf_0=\dfrac{hc}{\lambda}\)

	Threshold frequency
	The minimum frequency for a light photon to produce photoelectric effect.

Caesium	Lithium
Work function of caesium, \(W = 2.14\;eV\)	Work function of lithium, \(W = 2.14\;eV\)
Threshold frequency, \(f_0 = 5.16\times 10^{14}\text{ Hz}\)	Threshold frequency,\(f_0 = 6.03\times 10^{14}\text{ Hz}\)
Maximum wavelength to produce photoelectric current, \(\lambda = 579\text{ nm}\)	Maximum wavelength to produce photoelectric current, \(\lambda = 496\text{ nm}\)

Photoelectric Effect Applications

Solar panel
Light detectors at the automatic doors
Image sensor in high resolution cameras