Staircase and saw-tooth field emission steps from nanopatterned GaSb surfaces

M. Kildemo (1) , Y.I. Levinsen (2) , Séverine Le Roy (3) , E. Sondergard (3)

1 Physics Department, Norwegian University of Science and Technology
2 AB/RF CERN
3 SVI - Surface du Verre et Interfaces

High resolution field emission experiments from nanopatterned GaSb surfaces consisting of densely packed nanocones prepared by low ion-beam-energy sputtering is presented. Both uncovered and metal-covered nanopatterned surfaces were studied. The field emission surprisingly takes place by regular steps in the field emitted current. Depending on field, the steps are either regular flat plateaus or saw-tooth shaped. To our knowledge this is the first time that such results have been reported. Each discrete jump may be understood either as a resonant tunnelling effect causing the abrupt emission of a high aspect ratio single cone, or as a cascading effect where nearby cones switch on upon the on-set of the primary emitting cone with the highest field enhancement factor. The staircase shape may in both cases be understood from the spatial distribution of the aspect ratio of the cones. We find no evidence for a strong enhancement of the average field enhancement factor.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

M. Kildemo, Y.I. Levinsen, Séverine Le Roy, E. Sondergard. Staircase and saw-tooth field emission steps from nanopatterned GaSb surfaces. Journal of Vacuum Science & Technology A, 2009, 27 (5), pp.L18-L23. ⟨hal-00504472⟩