Nair AS, Kimura K. Charge transport behavior of N-(2-Mercaptopropionyl glycine)-protected gold clusters with temperature.
LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009;
25:1750-1756. [PMID:
19115942 DOI:
10.1021/la802997h]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
N-(2-Mercaptopropionyl glycine)-passivated gold clusters (Au-MPG) represent a unique networked system of monolayer-protected clusters (MPCs) due to inter- and/or intramolecular hydrogen bonding between the MPC units thanks to the terminal carboxylic acid groups of the monolayers. We have investigated the size-dependent electric charge transport in well-dried thin films of Au-MPG MPCs by a four-probe methodology as a function of temperature. The MPCs display a novel behavior of metallic-like-to-semiconductor crossover with increase of temperature. The MPCs having average cluster core sizes of approximately 1.6, approximately 3, and approximately 4 nm displayed a metallic-like nature (a linear increase of resistance of the films with increase of temperature) at low temperatures ( approximately 20-60 K), which crosses over to semiconductor behavior (decrease of resistance with increase of temperature) at high temperatures.
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