Phonon-assisted tunneling process in amorphous silicon nanostructures and GaAs nanowires

Abstract

Experimental results on the current–voltage ( I– V) characteristics of amorphous Si nanostructures reported by Irrera et al. [A. Irrera, F. Iacona, I. Crupil, C.D. Presti, G. Franzo, C. Bongiorno, D. Sanfilippo, G. Di Stefano, A. Piana, P.G. Fallica, A. Canino, F. Priolo, Nanotechnology 17 (2006) 1428] are reinterpreted in terms of a phonon-assisted tunneling model. It is shown that temperature dependence of current can be caused by the temperature dependence of electron tunneling rate from traps in the metal–semiconductor interface to the conduction band of the semiconductor. A good fit of experimental data with the theory is achieved in all measured temperature range from 30 to 290 K using for calculation the effective mass of 0.5 m e, and for the phonon energy the value of 12 meV. An advantage of this model over that of Irrera et al. used model is the possibility of describing the behavior of I– V data measured at both high and low temperatures with the same set of parameters characterizing this material. The temperature-dependent I– V data by Schricker et al. [A.D. Schricker, F.M. Davidson III, R.J. Wiacek, B.A. Korgel, Nanotechn. 17 (2006) 2681.] of GaAs nanowires, are also explained on the basis of this model.