InAs crystal embedded into silicon nanowire

This integration of crystals has been seen as the greatest obstacle in the creation of 'hetero nanowires. Previously, crystal lattice mismatch always led to numerous defects. The researchers say they have now managed to embed InAs crystals into the nanowires 'almost perfectly'. The process was carried out using ion beam synthesis and heat treatment with xenon flashlamps. A predetermined number of atoms was introduced into the wires using ion implantation, followed by flash lamp annealing of the silicon wires in their liquid phase, which took 20µs. "A 15nm thick silicon oxide shell maintains the form of the liquid nanowire," said HZDR scientist Dr Slawomir Prucnal, "while the implanted atoms form the InAs crystals." Dr Wolfgang Skorupa, head of the research group added: "The atoms diffuse in the liquid silicon phase so rapidly that, within milliseconds, they form flawless monocrystals, delineated from their surroundings with nearly perfect interfaces." In the next step of their work, the scientists want to implement different compound semiconductors into silicon nanowires and to optimise the size and distribution of the crystals. In the image, an InAs crystal (green) is embedded into the blue silicon nanowire.