Space charge neutralization by electron-transparent suspended graphene.
Graphene possesses many fascinating properties originating from the manifold potential for interactions at electronic, atomic, or molecular levels. Here we report measurement of electron transparency and hole charge induction response of a suspended graphene anode on top of a void channel formed in a SiO2/Si substrate. A two-dimensional (2D) electron gas induced at the oxide interface emits into air and makes a ballistic transport toward the suspended graphene. A small fraction (>~0.1%) of impinging electrons are captured at the edge of 2D hole system in graphene, demonstrating good transparency to very low energy (<3 eV) electrons. The hole charges induced in the suspended graphene anode have the effect of neutralizing the electron space charge in the void channel. This charge compensation dramatically enhances 2D electron gas emission at cathode to the level far surpassing the Child-Langmuir's space-charge-limited emission.
1] Department of Electrical and Computer Engineering and Petersen Institute of NanoScience and Engineering, 1140 Benedum, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States of America [2] [3].
Siwapon
S
Srisonphan
1] Department of Electrical and Computer Engineering and Petersen Institute of NanoScience and Engineering, 1140 Benedum, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States of America [2].
Myungji
M
Kim
Department of Electrical and Computer Engineering and Petersen Institute of NanoScience and Engineering, 1140 Benedum, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States of America.
Hong Koo
HK
Kim
D004579:Electron Transport; D004583:Electrons; D006108:Graphite / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties
D012822:Silicon Dioxide; D006108:Graphite