Germanium nanowire/conjugated semiconductor nanocomposite field effect transistors

Abstract

We demonstrate p-channel solution-processed nanocomposite field effect transistors based on a novel bilayer semiconductor of conjugated 6,13-bis(triisopropylsilylethinyl) pentacene (TIPS-PEN) or poly (3-octylthiophene-2,5-diyl) (P3OT) on an ordered network of germanium (Ge) nanowires. With an appropriate loading of Ge nanowires into the active channel, nanocomposite transistors show an enhancement of more than a factor of 10 over pristine devices. A hole carrier mobility as high as 0.248 cm(2) V(-1)s(-1) can be achieved based on the heterogeneous Ge/TIPS-PEN network. Moreover, the nanowire orientation relative to the source and drain contacts plays a crucial role in influencing the effective charge transport pathway and mobility anisotropy. It is expected that the nanocomposite FETs with oriented nanowire networks may open up a promising alternative route for the creation of next generation optoelectronic devices.