SKKU Advanced Institute of Nanotechnology, WCU Department of Energy Science, Graphene Center, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
Nano Lett. 2011 Nov 9;11(11):4682-7. doi: 10.1021/nl202266h. Epub 2011 Oct 10.
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.
持久光电导，一种持续数百秒的光致导通电行为，在半导体中已有观察。在此，我们报告了在石墨烯中存在持久的负光电导和连续显著的持久正光电导。观察到了异常大的负光电导（34%）和正光电导（1652%）的产量以及显著长的负瞬态响应时间（数小时）。这种高产量在多层石墨烯中减少，并在真空条件下被猝灭。二维金属石墨烯与环境和/或衬底强烈相互作用，导致了这种现象，这与三维半导体和纳米粒子明显不同。
