All‐Metallic Vertical Transistors Based on Stacked Dirac Materials
All‐Metallic Vertical Transistors Based on Stacked Dirac Materials
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DOI：
10.1002/adfm.201402904
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发表时间：
2014-08
影响因子：
19
通讯作者：
Yangyang Wang;Z. Ni;Qihang Liu;R. Quhe;Jiaxin Zheng;M. Ye;D. Yu;Jun-jie Shi;Jinbo Yang;
中科院分区：
文献类型：
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作者：
Yangyang Wang;Z. Ni;Qihang Liu;R. Quhe;Jiaxin Zheng;M. Ye;D. Yu;Jun-jie Shi;Jinbo Yang;
在场效应晶体管中使用金属作为沟道材料是一个持续的追求。所有的金属晶体管都可以用原始的半金属狄拉克材料（如石墨烯、硅烯和锗烯）制造，但开/关电流比非常低。在由两种狄拉克材料组成的垂直异质结构中，基于密度泛函理论方法，两种材料的狄拉克锥在弱层间范德华相互作用中幸存下来，因此由于动量失配，电子从一种材料的狄拉克锥向另一种材料的狄拉克锥的输移在没有声子辅助的情况下被禁止。全金属垂直Dirac材料异质结构器件的第一性原理量子输运模拟证实了输运间隙超过0.4 eV的存在，并且伴随着超过104的开关比。这种惊人的行为对两种狄拉克材料之间的相对旋转是稳健的，并且可以扩展到扭曲的双层石墨烯。因此，全金属结可以作为半导体，为高性能器件中的狄拉克材料垂直结构开辟了新的途径，而无需打开其带隙。
It is an ongoing pursuit to use metal as a channel material in a field effect transistor. All metallic transistor can be fabricated from pristine semimetallic Dirac materials (such as graphene, silicene, and germanene), but the on/off current ratio is very low. In a vertical heterostructure composed by two Dirac materials, the Dirac cones of the two materials survive the weak interlayer van der Waals interaction based on density functional theory method, and electron transport from the Dirac cone of one material to the one of the other material is therefore forbidden without assistance of phonon because of momentum mismatch. First‐principles quantum transport simulations of the all‐metallic vertical Dirac material heterostructure devices confirm the existence of a transport gap of over 0.4 eV, accompanied by a switching ratio of over 104. Such a striking behavior is robust against the relative rotation between the two Dirac materials and can be extended to twisted bilayer graphene. Therefore, all‐metallic junction can be a semiconductor and novel avenue is opened up for Dirac material vertical structures in high‐performance devices without opening their band gaps.