文摘
Although optical lithography is suited for producing intricate architectures, its combination with "bottom-up" approaches becomes a very challenging issue. The challenge is to electrically address the coordinatesof millions of nanoparticles (e.g., nanowires) on a given surface. Here, we describe a method that controlsthe registries of horizontally grown nanowires (NWs) and advances the current state-of-the-art NW deviceassembly technology. In this architecture, NWs are grown where the nanodevices will later be fabricatedon. There is no need to transfer NWs to a different surface or align them. With the use of only threephotolithographic steps, this technique allows industrial-scale production of nanodevices. First, an -planesapphire surface is patterned with gold nanodroplets. Next, small-diameter zinc oxide NWs are grownselectively on the predefined gold sites. Growth direction of the NW is controlled using the anisotropiccrystal match between zinc oxide and the underlying substrate. Subsequently, metal electrodes are depositedon NWs at once and in a parallel fashion. To demonstrate the capabilities of this method, large numbersof top-gated zinc oxide NW field-effect transistors are prepared using optical lithography. This fabricationmethod opens the path to a new generation of nonconventional nanodevices and nanosensors and couldimpact nanotechnology industries.