Photoemission from Silver into Sodium Chloride, Thallium Chloride, and Thallium Bromide

Abstract

The photoelectric work function for the transfer of electrons from a metal directly into an insulating crystal has been investigated for Ag on samples of NaCl, TlCl, and TlBr. The results obtained do not confirm the existence of this process in the samples studied although the apparatus had a current sensitivity of 1×${10}^{-17\mathrm{}}$ ampere. Mott and Gurney have suggested that the work function of the metal-insulator contact would be less than the vacuum work function of the metal by an amount equal to the electron affinity of the insulator. Previous experimental evidence supporting this picture of the contact appears less conclusive in the light of the results of this investigation.