Negative and Positive Persistent Photoconductance in Graphene

• Published in: Nano letters Vol. 11; no. 11; pp. 4682 - 4687
• Main Authors: Biswas, Chandan, Güneş, Fethullah, Loc, Duong Dinh, Lim, Seong Chu, Jeong, Mun Seok, Pribat, Didier, Lee, Young Hee
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 09.11.2011
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conduction; Cross-disciplinary physics: materials science; rheology; Electric Conductivity; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport phenomena in thin films and low-dimensional structures; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Graphene; Graphite - chemistry; Graphite - radiation effects; Light; Materials science; Materials Testing; Multilayers; Nanocrystalline materials; Nanoparticles; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Nanostructures - chemistry; Nanostructures - radiation effects; Photoconduction and photovoltaic effects; photodielectric effects; Physics; Quenching (cooling); Radiation Dosage; Semiconductors; Specific materials; Three dimensional; Transient responses; negative photoconductance; persistent photoconductance; Graphene; optoelectronics; positive photoconductance; Nanoparticles; Multilayers; Photoconduction; Semiconductor materials; Multilayer; Photoinduced effect; Photoconductivity; Nanostructured materials; Transients
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl202266h

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.