The Nature of CVC Nonlinearity in Low-Voltage Scanning Tunneling Spectroscopy of Semiconductors
Moscow State Technological University “STANKIN”, RU-127055, Moscow, Russian Federation;
* Corresponding author: firstname.lastname@example.org, tel.+79164919418
Published online: 26 April 2021
A new model of field emission in a scanning tunnelling microscope was developed. The model describes the tunnelling current from a surface of semiconductor (semimetal) and allows estimating the preexponential factor in the expression for the tunneling probability. It is shown that this factor is directly related to the degree of localization of the electron density and determines the shape of the local tunnel current-voltage characteristics (LTCVCs) at low voltages. The model allows separating the contributions of surface electronic states of different symmetry (dimension) of the tunnelling current. The practical application of the model is demonstrated by the example of mathematical processing of the LTCVCs of HOPG surface containing different structural defects.
Key words: charge tunneling / STM / STS / CVC / surface defects / monographite.
© The Authors, published by EDP Sciences, 2021
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