Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/7601
Title: The effects of electron-hole separation on the photoconductivity of individual metal oxide nanowires
Author: Prades García, Juan Daniel
Hernández Ramírez, Francisco
Jiménez Díaz, Román
Manzanares, M.
Andreu Arbella, Teresa
Cirera Hernández, Albert
Romano Rodríguez, Alberto
Morante i Lleonart, Joan Ramon
Keywords: Nanoestructures
Fotoconductivitat
ZnO nanowires
Nanostructures
Nanowires
Photoconductivity
Issue Date: 2008
Publisher: IOP Publishing
Abstract: The responses of individual ZnO nanowires to UV light demonstrate that the persistent photoconductivity (PPC) state is directly related to the electron¿hole separation near the surface. Our results demonstrate that the electrical transport in these nanomaterials is influenced by the surface in two different ways. On the one hand, the effective mobility and the density of free carriers are determined by recombination mechanisms assisted by the oxidizing molecules in air. This phenomenon can also be blocked by surface passivation. On the other hand, the surface built-in potential separates the photogenerated electron¿hole pairs and accumulates holes at the surface. After illumination, the charge separation makes the electron¿hole recombination difficult and originates PPC. This effect is quickly reverted after increasing either the probing current (self-heating by Joule dissipation) or the oxygen content in air (favouring the surface recombination mechanisms). The model for PPC in individual nanowires presented here illustrates the intrinsic potential of metal oxide nanowires to develop optoelectronic devices or optochemical sensors with better and new performances.
Note: Versió Postprint del document publicat a http://dx.doi.org/10.1088/0957-4484/19/46/465501
It is part of: Nanotechnology, 2008, vol. 19, p. 465501
URI: http://hdl.handle.net/2445/7601
ISSN: 1361-6528
Appears in Collections:Articles publicats en revistes (Electrònica)

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