Quantum confinement effects are observed in transport measurements of Cu2S nanocrystal based devices. Two nanocrystals sizes are studied, 3 nm being in the quantum-confinement regime, and 14 nm, lacking confinement. The effect of ligand length on the charge transport mechanism is studied via conductance temperature dependence measurements. While in the 14 nm nanocrystal based devices unique non-monotonic temperature dependence is observed, the 3 nm based devices show only thermally activated transport for all ligands. The difference is attributed to a cross-over from inter-particle hopping to intra-particle dominated transport as the ligand length increases. In the 3 nm devices the effect of ligand length on the charge-hopping activation energy is also discussed.
the online version of this article (DOI: 10.1515/zpch-2014-0593) provides supplementary material for authorized users.
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