Red border photo effect

The “red” border of the photoelectric effect is the lowest frequency $\nu _{min}$ ${\ displaystyle \ nu _ {min}}$ ${\ displaystyle \ nu _ {min}}$ (longest wavelength $\lambda _{max}$ ${\ displaystyle \ lambda _ {max}}$ $\ lambda _ {{max}}$ ) light , at which an external photoelectric effect is still possible, that is, the initial kinetic energy of photoelectrons is greater than zero. Frequency $\nu _{min}$ ${\ displaystyle \ nu _ {min}}$ ${\ displaystyle \ nu _ {min}}$ depends only on the output work $A_{out}$ ${\ displaystyle A_ {out}}$ $A_ {out}$ electron :

$\nu _{min}={\frac {A_{out}}{h}}$ ${\ displaystyle \ nu _ {min} = {\ frac {A_ {out}} {h}}}$ ${\ displaystyle \ nu _ {min} = {\ frac {A_ {out}} {h}}}$

$\lambda _{max}={\frac {hc}{A_{out}}}$ ${\ displaystyle \ lambda _ {max} = {\ frac {hc} {A_ {out}}}}$ $\ lambda _ {{max}} = {\ frac {hc} {A _ {{out}}}}$

Where $A_{out}$ ${\ displaystyle A_ {out}}$ $A_ {out}$ Is the work function for a particular photocathode , h is the Planck constant , and c is the speed of light . Exit work $A_{out}$ ${\ displaystyle A_ {out}}$ $A_ {out}$ depends on the material of the photocathode and the state of its surface. The emission of photoelectrons begins as soon as light is incident on the photocathode with a frequency $\nu =\nu _{min}$ ${\ displaystyle \ nu = \ nu _ {min}}$ ${\ displaystyle \ nu = \ nu _ {min}}$ or with wavelength $\lambda =\lambda _{max}$ ${\ displaystyle \ lambda = \ lambda _ {max}}$ ${\ displaystyle \ lambda = \ lambda _ {max}}$ .

Red border photoelectric effect for some substances

Substance	Red border ^[1]
Barium	484 nm
Barium in tungsten	1130 nm
Tungsten	272 nm
Germanium	272 nm
Nickel	249 nm
Barium oxide	1235 nm
Platinum	190 nm
Rubidium	573 nm
Silver	261 nm
Thorium on Tungsten	471 nm
Cesium	662 nm
Cesium on tungsten	909 nm
Cesium on platinum	895 nm

Notes

↑ A quick reference to physics. Enokhovich A.S. 2nd ed., Rev. and add. - M.: Higher School, 1976. - 288s. (see page 164)

[1] A quick reference to physics. Enokhovich A.S. 2nd ed., Rev. and add. - M.: Higher School, 1976. - 288s. (see page 164)

Red border photo effect

Red border photoelectric effect for some substances

See also

Notes

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