接触电极的功函数对基于碳纳米管构建的场效应管的影响

The influence of contact metal in carbon nanotube transistor

基于碳纳米管构建的场效应管在纳电子器件中占有重要的位置,如何获得p型和n型的电子输运性能是人们所关注的.本文分别采用高功函数的Pt金属和低功函数的Al金属作为源漏电极,获得了p型输运性质和n型输运性质的基于碳纳米管构建的场效应管.能带结构的分析证明了接触电极的功函数在这种场效应管的输运机理中扮演了重要的角色,可以仅仅通过改变接触电极的材料,实现p型场效应管和n型场效应管之间的转换,这是经典的金属与半导体接触的理论无法解释的.

We have fabricated p-type and n-type carbon nanotube transistors （CNTFETs） by using high and low work-function metals Pt and AI as contact electrodes, respectively. The band structures indicate that the work functions of contact metals play an important role in operation mechanism of CNTFETs. We can obtain fine-tuning of Schottky barrier heights for p- and n-channel conductions by changing the contact metals. These results can be explained by taking into account the work functions of the contact metals.