Screening and Variable Range Hopping Conduction in Silicon MOSFETs

L. Limouny ； A. El kaaouachi ； S. Dlimi ； A. Sybous ； A. Narjis ； M. Errai ； E. Daoudi

《Chinese Journal of Physics》 51卷6期 (2013/12) Pp. 1312-1320

https://doi.org/10.6122/CJP.51.1312

並列摘要

We re-analyze earlier published data on two dimensional electron system Si-MOSFETs sample of a two dimensional electron system in n-channel Si-MOSFETs down to 2K at zero magnetic field. The system is of low electron densities and near the metal-insulator transition point from the insulating side. Our results show the existence of a crossover, from Efros-Shklovskii variable range hopping (ES-VRH) characterized with the existence of a Coulomb gap and ρ=ρ0 exp(T(subscript ES)/T )^(1/2), to the Mott regime where ρ=ρ0 exp(T(subscript M)/T)^(1/3). With ρ0 is a pre-exponential factor that is found to be close to 2(h/e^2), and this crossover occurs when the value of temperature oscillates around 1 K.

參考文獻

N. V. Agrinskaya and A. N. Aleshin, Sov. Phys. Solid State 31, 1996 (1989).

A. Aharony, Y. Zhang, and M. P. Sarachik, Phys. Rev. Lett. 68, 3900 (1992).

B. I. Shklovskii and A. L. Efros, Electronic properties of doped semiconductors (Springer-Verlag, Berlin, 1984).

J. Mott, J. Non-Crystalline Solids 1, 1 (1968).

J. G. Massey and Mark Lee, Phys. Rev. B 62, R13 270 (2000).