Cold field emission dominated photoconductivity in ordered three-dimensional assemblies of octapod-shaped CdSe/CdS nanocrystals
KAUST DepartmentBiological and Environmental Sciences and Engineering (BESE) Division
Physical Sciences and Engineering (PSE) Division
Materials Science and Engineering Program
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AbstractSemiconductor nanocrystals, especially their ordered assemblies, are promising materials for various applications. In this paper, we investigate the photoconductive behavior of sub-micron size, ordered three-dimensional (3D) assemblies of octapod-shaped CdSe/CdS nanocrystals that are contacted by overlay electron-beam lithography. The regular structure of the assemblies leads to photocurrent-voltage curves that can be described by the cold field electron emission model. Mapping of the photoconductivity versus excitation wavelength and bias voltage allows the extraction of the band gap and identification of the photoactive region in the voltage and spectral domain. These results have important implications for the understanding of photoconductive transport in similar systems. © 2013 The Royal Society of Chemistry.
SponsorsL.M. acknowledges financial support from European Union through the FP7 starting ERC grant NANO-ARCH (contract number 240111).
PublisherRoyal Society of Chemistry