A theoretical study of field emission from p-type diamond films

In order to take advantage of the negative electron affinity (NEA) of diamond for low field electron emission, the Fermi level must be as high up in the band gap as possible. This could be achieved by doping the diamond with n-type dopants. But, unfortunately, reliable n-type doping has been difficult. Generally p-type semiconducting diamond is readily available. The low-field emission from p-type diamond has been experimentally observed. In theory, however, mechanisms for field emission from p-type diamond films have not well been understood. In this paper, a model has been developed which takes the NEA, band bending, impurity/defect ionization into account. The theoretical results can be used to explain the low-field emission and the weak temperature dependence of field emission from the p-type diamond films.