Photoelectron transfer through $p$-GaAs(Cs, O)–vacuum interface with positive and negative electron affinity

The evolution of the energy distributions of electrons emitted from $p$-GaAs(Cs, O), during the transition from negative to positive effective electron affinity upon the deposition of excess cesium has been studied. It was found that during the deposition of excess cesium the evolution of energy distributions is caused not only by the increase in surface work function, but also by the decrease in the probability of electron escape into vacuum. The results are compared with the experiment on excess oxygen adsorption. Presumably, the changes in the escape probability are caused by electron scattering on two-dimensional cesium clusters with metallic excitation spectrum.