Relation between conduction property and work function of contact metal in carbon nanotube field-effect transistors
2006; IOP Publishing; Volume: 17; Issue: 14 Linguagem: Inglês
10.1088/0957-4484/17/14/011
ISSN1361-6528
AutoresY Nosho, Yutaka Ohno, Shigeru Kishimoto, T. Mizutani,
Tópico(s)Nanowire Synthesis and Applications
ResumoWe have investigated the relation between the conduction property and the work function of the contact metal in carbon nanotube field-effect transistors (NTFETs). The conduction type and the drain current are dependent on the work function. In contrast to NTFETs with Ti and Pd contact electrodes, which showed p-type conduction behaviour, devices with Mg contact electrodes showed ambipolar characteristics and most of the devices with Ca contact electrodes showed n-type conduction behaviour. This indicates that the barrier height of the metal/nanotube contact is dependent on the work function of the contact metal, which suggests that the Fermi-level pinning is weak at the interface, in contrast to conventional semiconductors such as Si and GaAs. We have also demonstrated nonlinear rectification current–voltage characteristics in a nanotube quasi-pn diode with no impurity doping, in which different contact metals with different work functions are used for the anode and the cathode.
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