The electron affinity and ionization energy of various impurities in silicone oil

Electron affinities of various impurities and their electron emission ionization energies are presented. When electrons and holes were injected into silicone oil with a thin-film tunnel emitter, the injecting voltage was influenced by the type of impurity and its amount. The electron affinity for an impurity was calculated from the difference between the injecting voltage in pure silicone oil and the voltage in silicone oil contaminated with the impurity. The energy which is required for electron emission from the impurity was calculated from the hole injection voltage for the contaminated silicone oil. According to the experimental results, the electron affinity and the energy for electron emission depended on the structure of the impurity. Impurities with high electron affinity or high electron emission capability had either large dipole moments or many π electrons. Electron affinity of various impurities and the electron emission energy were mainly correlated to their acceptor number and their donor number, respectively