Semiconductor nanowires are structures with an extremely high aspect ratio and a diameter typically smaller than 100 nm that can be created in a bottom-up approach. Feature sizes down to 10 nm can be achieved without any lithography in many material systems. The quasi-one-dimensional shape, the nanometric size, and the comparably simple fabrication offer many conceptual advantages for various applications and make nanowires an exciting subject for fundamental studies. Many of the unique properties of nanowires are a direct consequence of their quasi one-dimensional shape and nanometric size and are independent of the material the nanowires consist of.
The goal of our research is to inspire and demonstrate new functionalities for optoelectronic applications by employing III-V nanowires. To this end, we investigate fundamental nanowire properties that crucially influence such applications and in particular light-emitting diodes. We grow both group-III-nitride and group-III-arsenide nanowires by molecular beam epitaxy, typically on silicon substrates and without any external catalyst. We analyze their microstructure and their optical as well as electronic properties, and we employ technology to guide growth, enable electrical measurements, and process demonstrator devices.