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A Study of Anomalous Conduction in n-Type Amorphous Silicon and Correlations in Conductivity and Noise in Gold Nanoparticle-Ligand Arrays

This work explores two very different structural systems: n-type hydrogenated amorphous silicon (a-Si:H) and gold nanoparticles (AuNPs) suspended in a matrix of organic ligands. For a-Si:H, examination of the gas-phase concentration of dopant (1-6% PH3/SiH4) and argon diluent effects includes the temperature dependent conductivity, low-frequency electronic noise, and Raman spectroscopy to examine structure. It is found that a-Si:H samples grown with high dopant concentration or with argon dilution exhibit an anomalous hopping conduction mechanism with an exponent of p=0.75. An experimental approach is used to determine correlations between conduction parameters, such as the pre-exponential factor and the characteristic temperature, rather than an analysis of existing models to explain the anomalous conduction. From these results, the anomalous conduction is a result of a change in the shape of the density of states and not a shift of the Fermi level with dopant. Additionally, it is found that argon dilution increases the carrier mobility, reduces the doping efficiency, and causes a degradation of the short-range order. With AuNPs, a comparison of temperature dependent conductivity and low-frequency noise shows that the temperature coefficient of resistance (TCR) is independent of the length of interparticle distance while the noise magnitude decreases.

Identiferoai:union.ndltd.org:unt.edu/info:ark/67531/metadc1833556
Date08 1900
CreatorsWestern, Brianna J
ContributorsLittler, Chris L, Syllaios, Athanasios J, Philipose, Usha, Lin, Yuankun, Glass, Gary
PublisherUniversity of North Texas
Source SetsUniversity of North Texas
LanguageEnglish
Detected LanguageEnglish
TypeThesis or Dissertation
Formatix, 105 pages, Text
RightsPublic, Western, Brianna J, Copyright, Copyright is held by the author, unless otherwise noted. All rights Reserved.

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