Temperature dependence of the photoelectron emission from intentionally oxidized copper

The characteristics of the photoelectron emission (PE), measured by varying the wavelength of incident light, form copper subjected to oxidation treatment in air have been investigated as a function of the measurement temperature between 25 and 300°C using a gas-flow counter. The intensity of PE at a certain measurement temperature decreased with increasing oxidation temperature (100 to 800°C) and the intensity of PE for a given oxidation temperature increased with decreasing measurement temperature. The PE behavior was correlated to the chemical and electrical nature of the surfaces analyzed by X-ray photoelectron spectroscopy and surface potential measurement. A mechanism is proposed for the PE of the untreated sample which exhibited a completely different PE behavior.