Au-free InAs nanowires grown in In-particle-assisted vapor-liquid-solid mode: growth, structure, and electrical property

We investigated the growth, structure, and electrical properties of InAs nanowires grown in the Au-free vapor-liquid-solid mode. We demonstrated the self-assisted vapor-liquid-solid growth of InAs nanowire with self-assembled In particles on InP substrates. We found that the III/V source mole ratio has a significant effect on the growth behavior and tapering shape. With a high III/V mole ratio (>0.11), a pure In particle at the tip of a nanowire makes it possible to grow the InAs nanowire in the self-assisted vapor-liquid-solid mode. We also found that the growth temperature range of the self-assisted vapor-liquid-solid growth was quite narrow compared with the conventional Au-assisted vapor-liquid-solid mode. A single InAs nanowire grown with a high III/V mole ratio exhibits distinct TO phonon peak in a Raman spectroscopy observation. We further verified that an undoped InAs nanowire grown in the self-assisted vapor-liquid-solid mode could function as a channel in a field-effect transistor device and the undoped nanowire exhibits n-type conduction behavior