A scheme that combines the non-equilibrium Green’s function method with the Korringa-Kohn-Rostoker (KKR) Green’s function method is proposes. The method is different from most previous attempts [1-3] in that it uses the exact Green’s function whose spectrum is not bound within a finite energy range, and hence, it provides sounder basis for quantitative discussions than the methods using the finite basis sets do. The scheme is applied to the Schottky junctions composed of a Al/GaN/Al trilayer.
Schottky contacts formed in metal/semiconductor junctions play an important role in semiconductor devices and integrated circuits [4]. They have been intensively investigated for several decades not only for possible application to electronic devices but also for gaining a fundamental understanding of the Schottky barrier formation.
Our results show that the Schottly barrier is formed between an undoped GaN and Al interface. The transport property of this system under various finite bias voltages is calculated. It is shown that the asymmetric behavior of electron transport against the direction of bias voltage occurs in this system, confirming the feature of rectification.
References
[1] J. M. Soler, E. Artacho, J. D. Gale, A. Garcia, J. Junquera, P. Ordejon, and D. Sanchez-Portal, J. Phys.: Condens. Matter 14, 2745 (2002).
[2] D. R. Bowler, T. Miyazaki, and M. J. Gillan, J. Phys.: ?Condens. Matter 14, 2781 (2002).
[3] T.Ozaki and H.Kino, Phys.Rev.B72,045121 (2005).
[4] S. M. Sze and K. K. Ng: Physics of Semiconductor Devices (John Willey and Sons, Hoboken, NJ, 2007)