title: Negative and positive persistent photoconductance in graphene.
abstract: Persistent photoconductance, a prolonged light-induced conducting behavior that lasts several hundred seconds, has been observed in semiconductors. Here we report persistent negative photoconductance and consecutive prominent persistent positive photoconductance in graphene. Unusually large yields of negative PC (34%) and positive PC (1652%) and remarkably long negative transient response time (several hours) were observed. Such high yields were reduced in multilayer graphene and were quenched under vacuum conditions. Two-dimensional metallic graphene strongly interacts with environment and/or substrate, causing this phenomenon, which is markedly different from that in three-dimensional semiconductors and nanoparticles.
authors.affiliation: SKKU Advanced Institute of Nanotechnology, WCU Department of Energy Science, Graphene Center, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Chandan
authors.initials: C
authors.lastname: Biswas
authors.forename: Fethullah
authors.initials: F
authors.lastname: Güneş
authors.forename: Dinh Loc
authors.initials: DL
authors.lastname: Duong
authors.forename: Seong Chu
authors.initials: SC
authors.lastname: Lim
authors.forename: Mun Seok
authors.initials: MS
authors.lastname: Jeong
authors.forename: Didier
authors.initials: D
authors.lastname: Pribat
authors.forename: Young Hee
authors.initials: YH
authors.lastname: Lee
mesh_terms: D004553:Electric Conductivity; D006108:Graphite / Q000737:chemistry* / Q000528:radiation effects*; D008027:Light; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects*; D011829:Radiation Dosage
chemical_list: D006108:Graphite