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Updated: May 28, 2026

Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
Published on: July 24, 2015
Negative and positive persistent photoconductance in graphene
Chandan Biswas1, Fethullah Güneş, Dinh Loc Duong
1SKKU Advanced Institute of Nanotechnology, WCU Department of Energy Science, Graphene Center, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
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.
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