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Persistent photoconductivity in ZnO nanostructures induced by surface oxygen vacancy
Author(s) -
Yin Z. G.,
Zhang X. W.,
Fu Z.,
Yang X. L.,
Wu J. L.,
Wu G. S.,
Gong L.,
Chu Paul K.
Publication year - 2012
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201105551
Subject(s) - metastability , photocurrent , photoconductivity , materials science , oxygen , relaxation (psychology) , vacancy defect , nanostructure , chemical physics , ionization , surface states , substrate (aquarium) , photochemistry , optoelectronics , chemistry , nanotechnology , surface (topology) , crystallography , psychology , social psychology , ion , geometry , mathematics , organic chemistry , oceanography , geology
ZnO nanowall networks grown on SiO 2 /Si substrate were found to exhibit persistent photoconductivity (PPC). The relaxation rate of the persistent photocurrent is enhanced by a higher oxygen level in the ambient suggesting that PPC is closely related to the ZnO surface. Surface modification with hydrogen peroxide can significantly reduce the PPC relaxation time, implying that surface oxygen deficiency is responsible for the effect. The transition between the neutral and the metastable singly ionized states of the surface oxygen vacancy is suggested to account for the phenomenon and it is supported by the temperature and wavelength dependence of the PPC. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)