Theoretical Study of a Zigzag Graphene Nanoribbon Field Effect Transistor
Theoretical Study of a Zigzag Graphene Nanoribbon
Field Effect Transistor
Hossein Karamitaheri, Mahdi Pourfath, Neophytos
Neophytou, Hans Kosina
Institute for Microelectronics, TU Wien, Gusshausstrasse
27-29/E360, 1040 Wien, Austria
E-mail: {karamitaheri | pourfath | neophytou | kosina}@iue.tuwien.ac.at Abstract
Graphene nanoribbons with zigzag edges show metallic behavior and are thus considered not appropriate for transistor applications. However, we show that by engineering line defects and using positive substrate impurities one can obtain a suitable effective transport gap at least for analog applications. The transfer and output characteristics of these structures are investigated employing quantum mechanical simulations and tightbinding model for the electronic structures.
Approach and Results
Graphene has received much attention for possible applications in nanoelectronics due to its excellent transport properties. However, as a zero band-gap material, graphene is not suitable for transistor applications. Graphene nanoribbons (GNRs) , on the other hand, are thin strips of graphene, whose electronic properties depend on the chirality of their edges and their width. Zigzag GNRs (ZGNRs) show metallic behavior, whereas armchair GNRs (AGNRs) are semiconductors with a band-gap inversely proportional to their width [1].
Therefore, AGNRs have been suggested recently as a channel material for transistors. For an optimal performance, the width (W) of the ribbons must be scaled down to 1-2 nm with an atomic edge precision. However, line-edge roughness and substrate impurities can significantly degrade their transport properties [2].
Although pristine ZGNRs are a zero band-gap material, as opposed to AGNRs, their ballistic transport can even be sustained in the presence of line edge roughness [3]. A bandgap, however needs to be achieved for transistor applications. In this work, we show that an “effective transport gap” can be
Field Effect Transistor
Hossein Karamitaheri, Mahdi Pourfath, Neophytos
Neophytou, Hans Kosina
Institute for Microelectronics, TU Wien, Gusshausstrasse
27-29/E360, 1040 Wien, Austria
E-mail: {karamitaheri | pourfath | neophytou | kosina}@iue.tuwien.ac.at Abstract
Graphene nanoribbons with zigzag edges show metallic behavior and are thus considered not appropriate for transistor applications. However, we show that by engineering line defects and using positive substrate impurities one can obtain a suitable effective transport gap at least for analog applications. The transfer and output characteristics of these structures are investigated employing quantum mechanical simulations and tightbinding model for the electronic structures.
Approach and Results
Graphene has received much attention for possible applications in nanoelectronics due to its excellent transport properties. However, as a zero band-gap material, graphene is not suitable for transistor applications. Graphene nanoribbons (GNRs) , on the other hand, are thin strips of graphene, whose electronic properties depend on the chirality of their edges and their width. Zigzag GNRs (ZGNRs) show metallic behavior, whereas armchair GNRs (AGNRs) are semiconductors with a band-gap inversely proportional to their width [1].
Therefore, AGNRs have been suggested recently as a channel material for transistors. For an optimal performance, the width (W) of the ribbons must be scaled down to 1-2 nm with an atomic edge precision. However, line-edge roughness and substrate impurities can significantly degrade their transport properties [2].
Although pristine ZGNRs are a zero band-gap material, as opposed to AGNRs, their ballistic transport can even be sustained in the presence of line edge roughness [3]. A bandgap, however needs to be achieved for transistor applications. In this work, we show that an “effective transport gap” can be
References: [1] M. Han et al., Phys. Rev. Lett. 98, 206805, 2007. [2] D. Basu et al., Appl. Phys. Lett. 92, 042114, 2008. [3] D. Areshkin et al., Nano Lett. 7, 204, 2007. [4] J. Lahiri et al., Nature Nanotech. 5, 326, 2010. [5] D. Bahamon et al., Phys. Rev. B 83. 155436, 2011. [6] D.-H. Kim and J. del Alamo, IEEE Int. Electr. Dev. Meet., p. 837, 2006.