Geometry dependent transport properties of undoped InAs nanowires

In recent time nanowire (NW) structures attracted much attention, for electronics, optoelectronics and fundamental quantum properties. On account of different application purposes basic transport properties are crucially important at room temperature as well as low temperatures. In this respect InAs NWs are particularly important due to the low band gap and high carrier concentration. We characterized the basic transport parameters of undoped InAs NWs at room temperature, which were grown on GaAs(001) substrate by MOVPE without catalyst. The NWs that we used in this work had diameters ranging from 25 nm to 200 nm and lengths up to 3.5 μm. Basic transport parameters, such as carrier concentration and mobility, were determined by using two- and four-terminal measurement configuration. The carrier concentration could be controlled by a SiO2 -isolated back-gate structure. By analyzing the transfer characteristics of the NW FET, we observed very good gate controllability.