Negative- and positive-temperature dependences of electron emission properties of hydrogen- and oxygen-terminated diamond field emitters

Temperature dependence of the electron emission properties of boron doped diamond thin film field emitters was investigated. We prepared both hydrogen- and oxygen-terminated diamond films with different boron concentrations. The oxygen-terminated emitters showed an enhanced emission current with an increase in the temperature. On the contrary, the hydrogen-terminated emitters showed a lowered emission current. These tendencies were observed irrespective of the boron concentration. The results suggested that the surface dipole greatly contributes to the emission property and the dipole moment is sensitive to the temperature.