Year: 2002
Type: article
Abstract: Transport properties of artificial solids composed of colloidal CdSe nanocrystals (NCs) are studied from 6 to 250 K, before and after annealing. After the solids are annealed, three changes are observed. First, transmission electron micrographs show that the separation between NCs decreases with annealing. Second, the optical absorption spectrum changes: the excitonic peaks of the NC solids shift to lower energies and broaden with annealing. These redshifts can result from the change of the dielectric environment around the NCs. Last, annealing results in greatly enhanced dark current and photocurrent. This increased current can be attributed to the enhancement of interdot tunneling caused by the decreased separation between NCs and by chemical changes in their organic cap. In addition, the dark current is an exponential function of the applied electric field and it is only weakly temperature dependent. Our measurements also suggest that Coulomb interactions between charges on neighboring NCs play an important role in the tunneling current.
Source: Journal of Applied Physics
DOI: 10.1063/1.1523148
Authors: M. Drndić, M. V. Jarosz, N. Y. Morgan, M. A. Kastner, M. G. Bawendi
Institution: Massachusetts Institute of Technology
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W3102766544