Atmospheric-pressure photoelectron emission from H-terminated and amino-terminated diamond

We report investigations of the ultraviolet-induced emission of electrons from diamond into air, argon, and SF6 gases at atmospheric pressure. Although diamond has long been known to be a facile emitter of electrons in vacuum, the present results show that H-terminated and amino-terminated diamond can also act as emitters of low-energy electrons into gases at atmospheric pressure. Present results show that emission currents follow the trend Ar > air > SF6. We attribute these differences to the fact that Ar does not form stable anions and the emitted electrons remain as free electrons with very low effective mass, while electrons in air form O-2(-) and electrons in SF6 form SF6- anions. The observed trends are consistent with trends reported in ion mobility measurements. Photoemission of electrons from diamond into argon gas at atmospheric pressure. (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim