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Transport properties of fullerene‐like WS 2 nanoparticles
Author(s) -
Kopnov F.,
Yoffe A.,
Leitus G.,
Tenne R.
Publication year - 2006
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200541170
Subject(s) - van der pauw method , pellets , electrical resistivity and conductivity , annealing (glass) , materials science , crystallite , nanoparticle , atmospheric temperature range , conductivity , arrhenius equation , electron mobility , hall effect , analytical chemistry (journal) , composite material , chemistry , nanotechnology , metallurgy , activation energy , thermodynamics , optoelectronics , physics , chromatography , electrical engineering , engineering
Electrical resistivity and Hall effect measurements of pellets compacted from fullerene‐like WS 2 nanoparticles ( IF ‐WS 2 ) and bulk 2H‐WS 2 powder were carried out using the van der Pauw method over a wide temperature range. In addition IF ‐WS 2 pellets were annealed at elevated temperatures under vacuum in a specially designed system. Arrhenius plots for the conductivities of the WS 2 samples (2H, IF and IF +annealing) exhibit marked uprise of ∂ ln ( sT –1 )/∂ T –1 with temperature. The resistivity of the non‐annealed IF ‐WS 2 pellets is higher by 2–8 orders of magnitude than that of 2H‐WS 2 pellets, whereas the resistivity of the annealed IF pellets is higher than that of the non‐annealed ones. Hall Effect measurements at 300 K show p‐type conductivity and similar carrier concentration for both types of materials. The carrier mobility of 2H‐WS 2 platelets is found to be in the range of the reported values. However, IF ‐WS 2 pellets have shown an unusually low mobility for a semiconducting material. The experimental data was found to be in a good agreement with a model used for analyzing the conductivity of polycrystalline semiconductors, which takes into consideration fluctuations of the barrier heights among the different nanoparticles as well as within a single nanoparticle boundary. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)