Photoelectron emission from aluminum and nickel measured in air

Abstract

Photoelectron emission from Al and Ni has been performed under atmospheric condtions. Measurements of photoemission current Ip as a function of oxide thickness yield attenuation lengths of 28 Å for Al2O3/Al and 71 Å for NiO/Ni for λ=2500 Å (∼5 eV). Photoemission from Al2O3/Al originates at the metal and is only attenuated by the oxide unless the oxide is bombarded with Ar+. After ion bombardment the oxide also emits electrons. Photoemission from NiO/Ni originates from the oxide for λ=2500 Å. Estimates of oxide film thickness can be made for very thin films (0∼200 Å) by very simple photoemission measurments in air.