Open AccessEffects of plasmonic coupling and electrical current on persistent photoconductivity of single-layer graphene on pristine and silver-nanoparticle-coated SiO_2/Si
Author(s) -
ChihYi Liu,
Kengchih Liang,
Chun-Cheng Chang,
Yonhua Tzeng
Publication year - 2012
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.022943
Subject(s) - photoconductivity , materials science , graphene , optoelectronics , plasmon , annealing (glass) , surface plasmon , nanotechnology , composite material
Effects and mechanisms of conductivity variation of chemically vapor deposited single-layer graphene covering silver nanoparticles on SiO(2)/Si are reported based on blue-light (405 nm) induced plasmonic coupling and electrical current induced annealing and desorption of surface adsorbates. With 1V applied voltage, photoconductivity is positive except a brief negative period when the graphene is first illuminated by light. At 10 mV applied voltage, negative photoconductivity persists for hours. In comparison, negative photoconductivity of graphene on pristine SiO(2)/Si persists for tens of hours. When the applied voltage is increased to 1V, it takes tens of hours of light illumination to change to positive photoconductivity.