Moreover, the shorter source-gate distance in the multiple-gate ZnO Selleckchem BTSA1 MOSFETs could increase the electric field intensity along the ZnO channel between the source electrode and the gate electrode, in comparison with that of the single-gate ZnO MOSFETs. The increased electric field intensity could cause a higher electron velocity [23, 24]. Therefore, the higher drain-source saturation current of

the multiple-gate ZnO MOSFETs could be obtained. Figure 3 Output characteristics of drain-source current. As a function of drain-source voltage for (a) single-gate ZnO MOSFETs and (b) multiple-gate ZnO MOSFETs. Transconductance (g m), which is defined as the slope of the drain-source current as a function of the gate-source voltage, is an important parameter of MOSFETs. The dependence of the transconductance on the gate-source voltage

of the single-gate ZnO MOSFETs and the multiple-gate ZnO MOSFETs operated at a drain-source voltage of 10 V was shown in Figure 4a,b, I-BET151 price respectively. The maximal transconductance of the single-gate ZnO MOSFETs and the multiple-gate ZnO MOSFETs was 3.93 and 5.35 mS/mm, respectively. It could be found that the transconductance of the multiple-gate MOSFETs was higher than that of the single-gate ZnO MOSFETs. This result indicated that the multiple-gate structure exhibited better channel transport control capability. The transconductance VX-680 cell line in the saturated velocity model is inversely proportional to the depletion width [22]. Therefore, the multiple-gate ZnO MOSFETs with a shorter effective gate length could

DCLK1 enhance the transconductance. Furthermore, the gate capacitance was increased by reducing the gate-source distance. The higher gate capacitance was also beneficial to an increase of the transconductance [24, 25]. Figure 4 Drain-source current and transconductance. As a function of gate-source voltage for (a) single-gate ZnO MOSFETs and (b) multiple-gate ZnO MOSFETs. In general, the gate-source electrical field (E GS) was relatively small in comparison with the gate-drain electrical field (E GD) since the gate-source voltage was smaller than the gate-drain voltage (V GD) [24]. The maximum gate-drain electrical field along the ZnO channel was located between the gate electrode and the drain electrode closed to the side of the gate electrode. It could be found that the gate-source electrical field enhancement was beneficial to the improvement of the drain-source current. In contrast, the larger maximum gate-drain electrical field was one reason of anomalous off-current. As shown in Figure 4, the anomalous off-current of the single-gate ZnO MOSFETs and the multiple-gate ZnO MOSFETs operated at a gate-source voltage of −4 V was 34 and 5.7 μA/mm, respectively. The off-current of the multiple-gate ZnO MOSFETs was lower than that of the single-gate ZnO MOSFETs. It could be expected that the multiple-gate structure had a lower maximum gate-drain electrical field as reported previously [21, 24].