碳纳米管薄膜晶体管中的接触电阻效应

利用不同功函数的金属作为接触电极,研究了网络状碳纳米管薄膜晶体管(CNT-TFT)的接触电阻效应。研究表明金属Pd与碳纳米管薄膜形成良好的欧姆接触, Au则形成近欧姆接触,这两种接触的器件的开态电流和迁移率较高。Ti和Al都与碳纳米管薄膜形成肖特基接触,且Al接触比Ti接触的势垒更高,接触电阻也更大,相应器件的开态电流和迁移率都较低。该结果表明对于CNT-TFT仍然可以通过接触来调控器件的性能,这对CNT-TFT的实用化进程具有重要的促进作用。

Contact Resistance Effects in Carbon Nanotube Thin Film Transistors

The contact resistance effect in the network type carbon nanotube thin film transistors (CNT-TFTs) is studied by using different contact metals. It is shown that palladium (Pd) can form an ohmic type contact with the carbon nanotube thin film, and gold (Au) forms an almost ohmic contact. On-state current and carrier mobility in the devices of these two contacts are high. In contrast, both titanium (Ti) and aluminum (Al) form Schottkytype contacts with the carbon nanotube thin film. The barrier height and the contact resistance of the Al contact are higher than those of the Ti contact. Therefore, the on-state current and carrier mobility are relatively low in the corresponding devices of these two types of contacts. These results indicate that the performance of CNTTFTs can be tuned by the contact metal, which is important for the commercialization of CNT-TFTs.