2007/11/30 by Elvira Ritz, Martin Dressel · 2 citations
Materials Science · Physics and Astronomy · #Glass properties and applications #Semiconductor materials and interfaces #Silicon Nanostructures and Photoluminescence #cond-mat.dis-nn #cond-mat.str-el
paper · pdf · doi:10.1002/pssc.200777583
published as Published in phys. stat. sol. (c) 5, No. 3, 703-707 (2008), http://www.interscience.wiley.com/ · 5 pages, 7 figures, conference "Transport in Interacting Disordered Systems" Marburg, August 6 - 10, 2007
openalex publication_date 2008/02/06 · arxiv created 2008/03/03 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Abstract At low energy scales charge transport in the insulating Si:P is dominated by activated hopping between the localized donor electron states. Thus, theoretical models for a disordered system with electron‐electron interaction are appropriate to interpret the electric conductivity spectra.With a newly developed technique we have measured the complex broadband microwave conductivity of Si:P from 100 MHz to 5 GHz in a broad range of phosphorus concentration n / n c from 0.56 to 0.95 relative to the critical value n c = 3:5 × 10 18 cm –3 corresponding to the metal‐insulator transition driven by doping. At our base temperature of T = 1.1 K the samples are in the zero‐phonon regime where they show a super‐linear frequency dependence of the conductivity indicating the influence of the Coulomb gap in the density of the impurity states. At higher doping n → n c , an abrupt drop in the conductivity power law σ 1 ( ω ) ∼ ω α is observed. The dielectric function ε 1 increases upon doping following a power law in (1 – n / n c ). Dynamic response at elevated temperatures has also been investigated. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)