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Establishing the relationship between the electrical transport properties of single-wall carbon nanotubes (SWCNTs) and their structures is critical for the design of high-performance SWCNT-based electronic and optoelectronic devices. Here, we systematically investigated the effect of the chiral structures of SWCNTs on their electrical transport properties by measuring the performance of thin-film transistors constructed by eleven distinct (n, m) single-chirality SWCNT films. The results show that, even for SWCNTs with the same diameters but different chiral angles, the difference in the on-state current or carrier mobility could reach an order of magnitude. Further analysis indicates that the electrical transport properties of SWCNTs have strong type and family dependence. With increasing chiral angle for the same-family SWCNTs, Type I SWCNTs exhibit increasing on-state current and mobility, while Type II SWCNTs show the reverse trend. The differences in the electrical properties of the same-family SWCNTs with different chiralities can be attributed to their different electronic band structures, which determine the contact barrier between electrodes and SWCNTs, intrinsic resistance and intertube contact resistance. Our present findings provide an important physical basis for performance optimization and application expansion of SWCNT-based devices. Single-wall carbon nanotubes have been reported in field effect transistors as a function of nanotube diameter, showing increasing current with increasing diameter. Su et al. show how the chiral structures of single-wall carbon nanotubes affect their electrical transport properties. [ABSTRACT FROM AUTHOR]

This letter reports on the realization of logic circuits employing solution-processed networks of single-walled carbon nanotubes. We constructed basic logic gates (inverter and NAND) with n- and p-type field-effect transistors fabricated by solution-based chemical doping. Complementary metal-oxide-semiconductor inverters exhibited voltage gains of up to 20, which illustrates the great potential of carbon nanotube networks for printable flexible electronics. [ABSTRACT FROM AUTHOR]

Local transport properties of a carbon nanotube (CNT) thin-film transistor (TFT) have been investigated by conducting atomic force microscopy. The current in a CNT bundle is almost constant, whereas it drastically decreases at the contacts between CNTs. Current drops at the contacts are reduced with increasing negative gate voltage VG. The results show that the contact resistance between CNTs can be modified by VG, and the operation of CNT-TFT is mainly governed by the modulation of contact resistance. [ABSTRACT FROM AUTHOR]

The authors fabricated random-network single-walled carbon nanotube field-effect transistors (FETs) with high-κ gate insulators. The gate insulator in the FETs was changed from SiO2 to Ba0.4Sr0.6Ti0.96O3 (BST, [variant_greek_epsilon]s=100), which was fabricated by a sol-gel method. The gate-switching voltage of a FET with a BST insulator is about one-tenth of that of a FET with a SiO2 insulator, and the values of the transconductance and the on/off ratio are 0.18 μS and 105, respectively. In addition, hysteresis in the operation of the FETs was dramatically decreased, probably because of improvements in the surface condition of the insulator. [ABSTRACT FROM AUTHOR]

We investigated a role of a Schottky barrier (SB) in carrier doped random-network single-walled carbon nanotube field effect transistors (RN-SWNT-FETs) and the precise estimation of the SB height by a suitable combination of the gate and source-drain voltages. The SB heights were 70 meV for hole and 100 meV for electron in p- and n-type FETs, respectively. Furthermore, the barrier height was able to be modulated by changing the doping level, which indicates the possibility of controlling the characteristics of RN-SWNT-FETs. [ABSTRACT FROM AUTHOR]

In the electrochemical transistor of a single-walled carbon nanotube, we introduced the fourth terminal, which works as a reference electrode. This enables accurate control of change in gate voltage, i.e., potential difference between the electrolyte and the source electrode, and quantitative analyses of the gate capacitance. We found that the geometrical capacitance, which was ignored in the conventional model, makes a crucial contribution to the device characteristics, comparable to that from the chemical capacitance. [ABSTRACT FROM AUTHOR]

The contact resistance (Rcont) between nanotube and metal electrodes was directly measured in a four-terminal configuration of field-effect transistors for individual single-walled carbon nanotube (SWNT) bundles and a multiwalled carbon nanotube (MWNT). Both Rcont and the nanotube resistance (RNT) in a semiconducting SWNT device drastically changed with gate voltage, while Rcont, being more than one-order smaller than Rcont in metallic SWNTs and MWNTs, was almost constant against the gate voltage. Carriers introduced either by gate voltage or chemical doping induced a rapid decrease in Rcont compared with the resistance of semiconducting SWNTs. [ABSTRACT FROM AUTHOR]