Study of the electrical conductivity at finite temperature in 2D Si- MOSFETs

Abstract

We investigate the low temperature density dependent conductivity of two dimensional electron systems in zero magnetic field for sample Si-15 MOSFETs. The first purpose of this paper is to establish that the knee of the conductivity σ0 (σ0 is the T = 0.3 conductivity obtained by linear extrapolation of the curves of σ (T) for different values of electron density, ns) as a function of the carrier densities ns for T = 0.3 K, observed by Lai et al. and Limouny et al. in previous work for two different samples, is independent of temperature. The second aim is the determination of the critical density, n c, of the metal-insulator transition. Many methods are used in this investigation of nc which have been already used for other samples. The motivation behind this last study is the observation of many values of nc that have been obtained from different methods and that are slightly different. We will use in this study three methods with the intention to infer which one is more appropriate to obtain nc. © 2014 AIP Publishing LLC.