New concepts based on semiconductor nanowires are intended to make transistors in microelectronic circuits better and more efficient. The faster the electrons in the tiny wires can accelerate, the faster a transistor can switch and the less energy it requires.
A research team from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), TU Dresden and NaMLab gGmbH has now succeeded in proving experimentally that the electron mobility in nanowires increases significantly when the sheath applies voltage to the wire core.
This was achieved with nanowires consisting of a gallium arsenide core and an indium aluminum arsenide sheath. The crystal structures in the sheath and core have slightly different lattice spacings. As a result, the sheath exerts a high mechanical stress on the much thinner core. The gallium arsenide in the core changes its electronic properties, the electrons become "lighter" and more mobile, so to speak. The team was able to show that electrons in the core of the wires studied move around 30 % faster at room temperature than in comparable nanowires without tension or thin-film materials made of gallium arsenide.
