The Energy Distribution of Electrons in the Photoelectric Effect

Abstract

The character of the photoelectric emission from a metal depends on the distribution of electron levels, the transition probabilities from these levels and the extent to which the levels are populated by electrons. The last of these is given by the Fermi factor. Various expressions have been suggested for the first two. These are discussed, and equations for the energy distribution derived in each case. The results are compared with experimental data for molybdenum, published by Roehr. In all cases the proportion of low energy electrons predicted appears to be too high. The theory of Mitchell comes nearest to fitting the experimental data over the low energy range. The stopping potential currents for higher energy, when plotted on a logarithmic scale as done by Roehr, fall nicely on the curve calculated on the theory of Mitchell. It is pointed out that the agreement obtained with such logarithmic plots is essentially a check on the dominating Fermi factor, and that the region of low energies in the energy distribution, for which the Fermi factor is practically unity, is the important one for studies of the electronic structure of metals.