1.
Maureen J Lagos Pedro A Autreto, Daniel Ugarte
Correlation between Quantum Conductance and Atomic Arrangement of Silver Atomic-Size Nanocontacts Conference
Correlation between Quantum Conductance and Atomic Arrangement of Silver Atomic-Size Nanocontacts, no. D1.3, MRSSpring 2012, 2012.
@conference{2012MRSSpring-D,
title = {Correlation between Quantum Conductance and Atomic Arrangement of Silver Atomic-Size Nanocontacts},
author = {Pedro A Autreto, Maureen J Lagos, Daniel Ugarte, Douglas S Galvao.},
url = {http://www.mrs.org/s12-program-d/
https://sites.ifi.unicamp.br/autretos/files/2015/04/2012MRSSpringMeeting-D-Program-Symposium-D-Nanocontacts–Emerging-Materials-and-Processing-for-Ohmicity-and-Rectification-2012-MRS-Spring-Meeting.pdf},
year = {2012},
date = {2012-04-10},
booktitle = {Correlation between Quantum Conductance and Atomic Arrangement of Silver Atomic-Size Nanocontacts},
number = {D1.3},
publisher = {MRSSpring 2012},
abstract = {The intense work of the nanotechnology community has increased the capabilities of researchers to produce new materials at the nanometric scale. As a result, novel physical and chemical behaviors are frequently reported opening opportunities for creating new kind of devices. These new devices will require a precise knowledge of the physical properties of atomic-size contacts and nanowires (NW)/interconnects. The generation of these atomic-size metal wires by the mechanical stretching has allowed the study of a wide range of metals at nanoscale. Due to the dominant role of surface energy in this size regime, several anomalous wire structures have already been reported to form during the stretching of very tiny wires, as hollow tubular metals and the size-limit to the existence of defects in NWs [1-3]. In this work we have studied the relevance of thermal effects on the structural and transport response of Ag atomic-size nanowires generated by mechanical elongation. Our study involve time-resolved atomic resolution transmission electron microscopy imaging and quantum conductance measurement using a ultra-high-vacuum mechanically he controllable break junction in association with quantum transport calculations. We have observed drastic changes in conductance and structural properties of Ag nanowires generated at different temperatures (150 and 300 K). By combining electron microscopy images, electronic transport measurements and theoretical modeling we have been able to establish a consistent correlation between the conductance and structural properties of Ag NWs. In particular, our study has revealed the formation of metastable rectangular rod-like Ag wire (3/3) along [001] direction. [1] M. J. Lagos, F. Sato, J. Bettini, V. Rodrigues, D. S. Galvao and D. Ugarte, Nature Nanotechnology v4, 149 (2009) [2] P. A. S. Autreto, M. J. Lagos, F. Sato, J. Bettini, V. Rodrigues, D. Ugarte, and D. S. Galvao, Phys. Rev. Lett. v106, 065501 (2011). [3] M. J. Lagos, F. Sato, D. S. Galvão, and D. Ugarte, Phys. Rev. Lett. v106, 055501 (2011).},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The intense work of the nanotechnology community has increased the capabilities of researchers to produce new materials at the nanometric scale. As a result, novel physical and chemical behaviors are frequently reported opening opportunities for creating new kind of devices. These new devices will require a precise knowledge of the physical properties of atomic-size contacts and nanowires (NW)/interconnects. The generation of these atomic-size metal wires by the mechanical stretching has allowed the study of a wide range of metals at nanoscale. Due to the dominant role of surface energy in this size regime, several anomalous wire structures have already been reported to form during the stretching of very tiny wires, as hollow tubular metals and the size-limit to the existence of defects in NWs [1-3]. In this work we have studied the relevance of thermal effects on the structural and transport response of Ag atomic-size nanowires generated by mechanical elongation. Our study involve time-resolved atomic resolution transmission electron microscopy imaging and quantum conductance measurement using a ultra-high-vacuum mechanically he controllable break junction in association with quantum transport calculations. We have observed drastic changes in conductance and structural properties of Ag nanowires generated at different temperatures (150 and 300 K). By combining electron microscopy images, electronic transport measurements and theoretical modeling we have been able to establish a consistent correlation between the conductance and structural properties of Ag NWs. In particular, our study has revealed the formation of metastable rectangular rod-like Ag wire (3/3) along [001] direction. [1] M. J. Lagos, F. Sato, J. Bettini, V. Rodrigues, D. S. Galvao and D. Ugarte, Nature Nanotechnology v4, 149 (2009) [2] P. A. S. Autreto, M. J. Lagos, F. Sato, J. Bettini, V. Rodrigues, D. Ugarte, and D. S. Galvao, Phys. Rev. Lett. v106, 065501 (2011). [3] M. J. Lagos, F. Sato, D. S. Galvão, and D. Ugarte, Phys. Rev. Lett. v106, 055501 (2011).
2.
Pedro A Autreto Ricardo P dos Santos, Eric Perim
On the Unzipping Mechanisms of Carbon Nanotubes: Insights from Reactive Molecular Dynamics Simulations, no. DD1.4, MRSSpring 2012, 2012.
@conference{2012MRSSpring-DD,
title = {On the Unzipping Mechanisms of Carbon Nanotubes: Insights from Reactive Molecular Dynamics Simulations},
author = {Ricardo P dos Santos, Pedro A Autreto, Eric Perim, Gustavo Brunetto, Douglas S Galvao},
url = {http://www.mrs.org/s12-program-dd/
https://sites.ifi.unicamp.br/autretos/files/2015/04/2012MRSSpringMeeting-DD-Program-Symposium-D-Nanocontacts–Emerging-Materials-and-Processing-for-Ohmicity-and-Rectification-2012-MRS-Spring-Meeting.pdf},
year = {2012},
date = {2012-04-09},
booktitle = {On the Unzipping Mechanisms of Carbon Nanotubes: Insights from Reactive Molecular Dynamics Simulations},
number = {DD1.4},
publisher = {MRSSpring 2012},
abstract = {Graphene has been one of the hottest topics in materials science today. Due to its unique and unusual electronic properties graphene is been considered one of the most promising materials for the basis of a new nanoelectronics. However, in its pristine form graphene is a zero-gap semiconductor. This poses serious limitations to its use in some kind of electronic applications (some kind of transistors). In order to create non-zero graphene-like structures many approaches have been tried, such as, hydrogenation, fluorination and/or other chemical and physical functionalizations, with limited success. It has also been shown that making thin graphene stripes, the so-called graphene nanoribbons (GNRs), it is possible to create non-zero structures with some control of the process. But large scale and controlled GNR synthesis has been proved to be very difficult. Another possibility of producing GNR in a more controllable way is through cutting (unzipping) carbon nanotubes (CNTs). This has been achieved with different chemical [1] and physical [2] approaches. However, in spite of many experimental and theoretical studies on this problem, some important aspects remain to be fully understood. In this work we investigated the process of CNT fracture (unzipping) through molecular dynamics simulations using reactive force fields (ReaxFF), as implemented in the LAMMPS code. We considered multi-walled CNTs of different dimensions and chiralities and under mechanical stretching. Our results show that the unzipping mechanisms are highly dependent on CNT chirality. Well defined and distinct fracture patterns were observed for different chiralities. Zig-zag CNTs favor the creation of GNRs with well defined armchair edges, while armchair and chiral CNTs produde GNRs with less defined (defective) edges. The reasons why almost perfect linear CNT cuts are so frequently observed are also addressed. [1] D. V. Kosynkin et al., Nature v458, 872 (2009). [2] L. Jiao et al, Nature v458, 877 (2009).},
keywords = {},
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Graphene has been one of the hottest topics in materials science today. Due to its unique and unusual electronic properties graphene is been considered one of the most promising materials for the basis of a new nanoelectronics. However, in its pristine form graphene is a zero-gap semiconductor. This poses serious limitations to its use in some kind of electronic applications (some kind of transistors). In order to create non-zero graphene-like structures many approaches have been tried, such as, hydrogenation, fluorination and/or other chemical and physical functionalizations, with limited success. It has also been shown that making thin graphene stripes, the so-called graphene nanoribbons (GNRs), it is possible to create non-zero structures with some control of the process. But large scale and controlled GNR synthesis has been proved to be very difficult. Another possibility of producing GNR in a more controllable way is through cutting (unzipping) carbon nanotubes (CNTs). This has been achieved with different chemical [1] and physical [2] approaches. However, in spite of many experimental and theoretical studies on this problem, some important aspects remain to be fully understood. In this work we investigated the process of CNT fracture (unzipping) through molecular dynamics simulations using reactive force fields (ReaxFF), as implemented in the LAMMPS code. We considered multi-walled CNTs of different dimensions and chiralities and under mechanical stretching. Our results show that the unzipping mechanisms are highly dependent on CNT chirality. Well defined and distinct fracture patterns were observed for different chiralities. Zig-zag CNTs favor the creation of GNRs with well defined armchair edges, while armchair and chiral CNTs produde GNRs with less defined (defective) edges. The reasons why almost perfect linear CNT cuts are so frequently observed are also addressed. [1] D. V. Kosynkin et al., Nature v458, 872 (2009). [2] L. Jiao et al, Nature v458, 877 (2009).
3.
Bruno I. Santos Gustavo Brunetto, Pedro A. Autreto; Galvao, Douglas S.
A Nonzero Gap Two-Dimensional Carbon Allotrope from Porous Graphene Conference
A Nonzero Gap Two-Dimensional Carbon Allotrope from Porous Graphene, no. AA15.102, MRS, 2011.
@conference{2011MRSFall,
title = {A Nonzero Gap Two-Dimensional Carbon Allotrope from Porous Graphene},
author = {Gustavo Brunetto, Bruno I. Santos, Pedro A. Autreto, Leonardo D. Machado, R. dos Santos and Douglas S. Galvao},
url = {http://www.mrs.org/f11-abstracts-aa/
https://sites.ifi.unicamp.br/autretos/files/2015/04/2011MRSFallMeeting-AA-Abstracts-Symposium-AA-Carbon-Nanotubes-Graphene-and-Related-Nanostructures..2011-MRS-Fall-Meeting.pdf},
year = {2011},
date = {2011-12-02},
booktitle = {A Nonzero Gap Two-Dimensional Carbon Allotrope from Porous Graphene},
number = {AA15.102},
publisher = {MRS},
abstract = {In the last decades many new carbon-based materials have been discovered. Examples of these materials are fullerenes, carbon nanotubes and graphene. Graphene has been one of the hottest topics in materials science in the last years. Graphene is a two dimensional array of hexagonal units of sp2 bonded carbon atoms with very unusual and interesting electronic and mechanical properties. Because of its special electronic properties, graphene is considered one of the most promising materials for future electronics. However, in its pristine state graphene is a gapless semiconductor, which poses some limitations to its use in some transistor electronics. Many approaches have been tried to create, in a controlled way, a gap in graphene. Among these approaches we can mention oxidation and chemical functionalizations. Hydrogenated graphene-like structures have been recently synthesized, as the so-called porous graphene [1]. In this work we show, based on ab initio quantum molecular dynamics calculations, that porous graphene dehydrogenation can lead to a spontaneous formation of a nonzero gap two-dimensional carbon allotrope, called biphenylene carbon (BC). This structure presents the ideal properties to electronic applications. Besides exhibiting an intrinsic nonzero gap, BC also presents well delocalized frontier orbitals, suggestive of a structure with high electronic mobility. Possible synthetic routes to obtain BC are addressed. [1] Y. F. Li, Z. Zhou, P. W. Shen, and Z. F. Chen, Chem. Commun. v46, 3672 (2010).},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
In the last decades many new carbon-based materials have been discovered. Examples of these materials are fullerenes, carbon nanotubes and graphene. Graphene has been one of the hottest topics in materials science in the last years. Graphene is a two dimensional array of hexagonal units of sp2 bonded carbon atoms with very unusual and interesting electronic and mechanical properties. Because of its special electronic properties, graphene is considered one of the most promising materials for future electronics. However, in its pristine state graphene is a gapless semiconductor, which poses some limitations to its use in some transistor electronics. Many approaches have been tried to create, in a controlled way, a gap in graphene. Among these approaches we can mention oxidation and chemical functionalizations. Hydrogenated graphene-like structures have been recently synthesized, as the so-called porous graphene [1]. In this work we show, based on ab initio quantum molecular dynamics calculations, that porous graphene dehydrogenation can lead to a spontaneous formation of a nonzero gap two-dimensional carbon allotrope, called biphenylene carbon (BC). This structure presents the ideal properties to electronic applications. Besides exhibiting an intrinsic nonzero gap, BC also presents well delocalized frontier orbitals, suggestive of a structure with high electronic mobility. Possible synthetic routes to obtain BC are addressed. [1] Y. F. Li, Z. Zhou, P. W. Shen, and Z. F. Chen, Chem. Commun. v46, 3672 (2010).
2012
3.
Maureen J Lagos Pedro A Autreto, Daniel Ugarte
Correlation between Quantum Conductance and Atomic Arrangement of Silver Atomic-Size Nanocontacts Conference
Correlation between Quantum Conductance and Atomic Arrangement of Silver Atomic-Size Nanocontacts, no. D1.3, MRSSpring 2012, 2012.
Abstract | Links | BibTeX | Tags: ab initio, conductance, molecular dynamics, nanowires
@conference{2012MRSSpring-D,
title = {Correlation between Quantum Conductance and Atomic Arrangement of Silver Atomic-Size Nanocontacts},
author = {Pedro A Autreto, Maureen J Lagos, Daniel Ugarte, Douglas S Galvao.},
url = {http://www.mrs.org/s12-program-d/
https://sites.ifi.unicamp.br/autretos/files/2015/04/2012MRSSpringMeeting-D-Program-Symposium-D-Nanocontacts–Emerging-Materials-and-Processing-for-Ohmicity-and-Rectification-2012-MRS-Spring-Meeting.pdf},
year = {2012},
date = {2012-04-10},
booktitle = {Correlation between Quantum Conductance and Atomic Arrangement of Silver Atomic-Size Nanocontacts},
number = {D1.3},
publisher = {MRSSpring 2012},
abstract = {The intense work of the nanotechnology community has increased the capabilities of researchers to produce new materials at the nanometric scale. As a result, novel physical and chemical behaviors are frequently reported opening opportunities for creating new kind of devices. These new devices will require a precise knowledge of the physical properties of atomic-size contacts and nanowires (NW)/interconnects. The generation of these atomic-size metal wires by the mechanical stretching has allowed the study of a wide range of metals at nanoscale. Due to the dominant role of surface energy in this size regime, several anomalous wire structures have already been reported to form during the stretching of very tiny wires, as hollow tubular metals and the size-limit to the existence of defects in NWs [1-3]. In this work we have studied the relevance of thermal effects on the structural and transport response of Ag atomic-size nanowires generated by mechanical elongation. Our study involve time-resolved atomic resolution transmission electron microscopy imaging and quantum conductance measurement using a ultra-high-vacuum mechanically he controllable break junction in association with quantum transport calculations. We have observed drastic changes in conductance and structural properties of Ag nanowires generated at different temperatures (150 and 300 K). By combining electron microscopy images, electronic transport measurements and theoretical modeling we have been able to establish a consistent correlation between the conductance and structural properties of Ag NWs. In particular, our study has revealed the formation of metastable rectangular rod-like Ag wire (3/3) along [001] direction. [1] M. J. Lagos, F. Sato, J. Bettini, V. Rodrigues, D. S. Galvao and D. Ugarte, Nature Nanotechnology v4, 149 (2009) [2] P. A. S. Autreto, M. J. Lagos, F. Sato, J. Bettini, V. Rodrigues, D. Ugarte, and D. S. Galvao, Phys. Rev. Lett. v106, 065501 (2011). [3] M. J. Lagos, F. Sato, D. S. Galvão, and D. Ugarte, Phys. Rev. Lett. v106, 055501 (2011).},
keywords = {ab initio, conductance, molecular dynamics, nanowires},
pubstate = {published},
tppubtype = {conference}
}
The intense work of the nanotechnology community has increased the capabilities of researchers to produce new materials at the nanometric scale. As a result, novel physical and chemical behaviors are frequently reported opening opportunities for creating new kind of devices. These new devices will require a precise knowledge of the physical properties of atomic-size contacts and nanowires (NW)/interconnects. The generation of these atomic-size metal wires by the mechanical stretching has allowed the study of a wide range of metals at nanoscale. Due to the dominant role of surface energy in this size regime, several anomalous wire structures have already been reported to form during the stretching of very tiny wires, as hollow tubular metals and the size-limit to the existence of defects in NWs [1-3]. In this work we have studied the relevance of thermal effects on the structural and transport response of Ag atomic-size nanowires generated by mechanical elongation. Our study involve time-resolved atomic resolution transmission electron microscopy imaging and quantum conductance measurement using a ultra-high-vacuum mechanically he controllable break junction in association with quantum transport calculations. We have observed drastic changes in conductance and structural properties of Ag nanowires generated at different temperatures (150 and 300 K). By combining electron microscopy images, electronic transport measurements and theoretical modeling we have been able to establish a consistent correlation between the conductance and structural properties of Ag NWs. In particular, our study has revealed the formation of metastable rectangular rod-like Ag wire (3/3) along [001] direction. [1] M. J. Lagos, F. Sato, J. Bettini, V. Rodrigues, D. S. Galvao and D. Ugarte, Nature Nanotechnology v4, 149 (2009) [2] P. A. S. Autreto, M. J. Lagos, F. Sato, J. Bettini, V. Rodrigues, D. Ugarte, and D. S. Galvao, Phys. Rev. Lett. v106, 065501 (2011). [3] M. J. Lagos, F. Sato, D. S. Galvão, and D. Ugarte, Phys. Rev. Lett. v106, 055501 (2011).
2.
Pedro A Autreto Ricardo P dos Santos, Eric Perim
On the Unzipping Mechanisms of Carbon Nanotubes: Insights from Reactive Molecular Dynamics Simulations, no. DD1.4, MRSSpring 2012, 2012.
Abstract | Links | BibTeX | Tags: carbon nanotubes, mechanical properties, molecular dynamics, reaxFF
@conference{2012MRSSpring-DD,
title = {On the Unzipping Mechanisms of Carbon Nanotubes: Insights from Reactive Molecular Dynamics Simulations},
author = {Ricardo P dos Santos, Pedro A Autreto, Eric Perim, Gustavo Brunetto, Douglas S Galvao},
url = {http://www.mrs.org/s12-program-dd/
https://sites.ifi.unicamp.br/autretos/files/2015/04/2012MRSSpringMeeting-DD-Program-Symposium-D-Nanocontacts–Emerging-Materials-and-Processing-for-Ohmicity-and-Rectification-2012-MRS-Spring-Meeting.pdf},
year = {2012},
date = {2012-04-09},
booktitle = {On the Unzipping Mechanisms of Carbon Nanotubes: Insights from Reactive Molecular Dynamics Simulations},
number = {DD1.4},
publisher = {MRSSpring 2012},
abstract = {Graphene has been one of the hottest topics in materials science today. Due to its unique and unusual electronic properties graphene is been considered one of the most promising materials for the basis of a new nanoelectronics. However, in its pristine form graphene is a zero-gap semiconductor. This poses serious limitations to its use in some kind of electronic applications (some kind of transistors). In order to create non-zero graphene-like structures many approaches have been tried, such as, hydrogenation, fluorination and/or other chemical and physical functionalizations, with limited success. It has also been shown that making thin graphene stripes, the so-called graphene nanoribbons (GNRs), it is possible to create non-zero structures with some control of the process. But large scale and controlled GNR synthesis has been proved to be very difficult. Another possibility of producing GNR in a more controllable way is through cutting (unzipping) carbon nanotubes (CNTs). This has been achieved with different chemical [1] and physical [2] approaches. However, in spite of many experimental and theoretical studies on this problem, some important aspects remain to be fully understood. In this work we investigated the process of CNT fracture (unzipping) through molecular dynamics simulations using reactive force fields (ReaxFF), as implemented in the LAMMPS code. We considered multi-walled CNTs of different dimensions and chiralities and under mechanical stretching. Our results show that the unzipping mechanisms are highly dependent on CNT chirality. Well defined and distinct fracture patterns were observed for different chiralities. Zig-zag CNTs favor the creation of GNRs with well defined armchair edges, while armchair and chiral CNTs produde GNRs with less defined (defective) edges. The reasons why almost perfect linear CNT cuts are so frequently observed are also addressed. [1] D. V. Kosynkin et al., Nature v458, 872 (2009). [2] L. Jiao et al, Nature v458, 877 (2009).},
keywords = {carbon nanotubes, mechanical properties, molecular dynamics, reaxFF},
pubstate = {published},
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}
Graphene has been one of the hottest topics in materials science today. Due to its unique and unusual electronic properties graphene is been considered one of the most promising materials for the basis of a new nanoelectronics. However, in its pristine form graphene is a zero-gap semiconductor. This poses serious limitations to its use in some kind of electronic applications (some kind of transistors). In order to create non-zero graphene-like structures many approaches have been tried, such as, hydrogenation, fluorination and/or other chemical and physical functionalizations, with limited success. It has also been shown that making thin graphene stripes, the so-called graphene nanoribbons (GNRs), it is possible to create non-zero structures with some control of the process. But large scale and controlled GNR synthesis has been proved to be very difficult. Another possibility of producing GNR in a more controllable way is through cutting (unzipping) carbon nanotubes (CNTs). This has been achieved with different chemical [1] and physical [2] approaches. However, in spite of many experimental and theoretical studies on this problem, some important aspects remain to be fully understood. In this work we investigated the process of CNT fracture (unzipping) through molecular dynamics simulations using reactive force fields (ReaxFF), as implemented in the LAMMPS code. We considered multi-walled CNTs of different dimensions and chiralities and under mechanical stretching. Our results show that the unzipping mechanisms are highly dependent on CNT chirality. Well defined and distinct fracture patterns were observed for different chiralities. Zig-zag CNTs favor the creation of GNRs with well defined armchair edges, while armchair and chiral CNTs produde GNRs with less defined (defective) edges. The reasons why almost perfect linear CNT cuts are so frequently observed are also addressed. [1] D. V. Kosynkin et al., Nature v458, 872 (2009). [2] L. Jiao et al, Nature v458, 877 (2009).
2011
1.
Bruno I. Santos Gustavo Brunetto, Pedro A. Autreto; Galvao, Douglas S.
A Nonzero Gap Two-Dimensional Carbon Allotrope from Porous Graphene Conference
A Nonzero Gap Two-Dimensional Carbon Allotrope from Porous Graphene, no. AA15.102, MRS, 2011.
Abstract | Links | BibTeX | Tags: molecular dynamics, porous graphene
@conference{2011MRSFall,
title = {A Nonzero Gap Two-Dimensional Carbon Allotrope from Porous Graphene},
author = {Gustavo Brunetto, Bruno I. Santos, Pedro A. Autreto, Leonardo D. Machado, R. dos Santos and Douglas S. Galvao},
url = {http://www.mrs.org/f11-abstracts-aa/
https://sites.ifi.unicamp.br/autretos/files/2015/04/2011MRSFallMeeting-AA-Abstracts-Symposium-AA-Carbon-Nanotubes-Graphene-and-Related-Nanostructures..2011-MRS-Fall-Meeting.pdf},
year = {2011},
date = {2011-12-02},
booktitle = {A Nonzero Gap Two-Dimensional Carbon Allotrope from Porous Graphene},
number = {AA15.102},
publisher = {MRS},
abstract = {In the last decades many new carbon-based materials have been discovered. Examples of these materials are fullerenes, carbon nanotubes and graphene. Graphene has been one of the hottest topics in materials science in the last years. Graphene is a two dimensional array of hexagonal units of sp2 bonded carbon atoms with very unusual and interesting electronic and mechanical properties. Because of its special electronic properties, graphene is considered one of the most promising materials for future electronics. However, in its pristine state graphene is a gapless semiconductor, which poses some limitations to its use in some transistor electronics. Many approaches have been tried to create, in a controlled way, a gap in graphene. Among these approaches we can mention oxidation and chemical functionalizations. Hydrogenated graphene-like structures have been recently synthesized, as the so-called porous graphene [1]. In this work we show, based on ab initio quantum molecular dynamics calculations, that porous graphene dehydrogenation can lead to a spontaneous formation of a nonzero gap two-dimensional carbon allotrope, called biphenylene carbon (BC). This structure presents the ideal properties to electronic applications. Besides exhibiting an intrinsic nonzero gap, BC also presents well delocalized frontier orbitals, suggestive of a structure with high electronic mobility. Possible synthetic routes to obtain BC are addressed. [1] Y. F. Li, Z. Zhou, P. W. Shen, and Z. F. Chen, Chem. Commun. v46, 3672 (2010).},
keywords = {molecular dynamics, porous graphene},
pubstate = {published},
tppubtype = {conference}
}
In the last decades many new carbon-based materials have been discovered. Examples of these materials are fullerenes, carbon nanotubes and graphene. Graphene has been one of the hottest topics in materials science in the last years. Graphene is a two dimensional array of hexagonal units of sp2 bonded carbon atoms with very unusual and interesting electronic and mechanical properties. Because of its special electronic properties, graphene is considered one of the most promising materials for future electronics. However, in its pristine state graphene is a gapless semiconductor, which poses some limitations to its use in some transistor electronics. Many approaches have been tried to create, in a controlled way, a gap in graphene. Among these approaches we can mention oxidation and chemical functionalizations. Hydrogenated graphene-like structures have been recently synthesized, as the so-called porous graphene [1]. In this work we show, based on ab initio quantum molecular dynamics calculations, that porous graphene dehydrogenation can lead to a spontaneous formation of a nonzero gap two-dimensional carbon allotrope, called biphenylene carbon (BC). This structure presents the ideal properties to electronic applications. Besides exhibiting an intrinsic nonzero gap, BC also presents well delocalized frontier orbitals, suggestive of a structure with high electronic mobility. Possible synthetic routes to obtain BC are addressed. [1] Y. F. Li, Z. Zhou, P. W. Shen, and Z. F. Chen, Chem. Commun. v46, 3672 (2010).
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