Vapor-Liquid-Solid Growth of Semiconductor Nanowires

The vapor-liquid-solid (VLS) growth technique has advanced significantly over the past several decades. This technique has progressed from an interesting method for whisker growth to a viable approach for semiconductor nanowire fabrication for applications in nanoscale electronics, optoelectronics, sensing, and energy conversion. This chapter reviews fundamental aspects of VLS growth with an emphasis on synthesis within a chemical vapor deposition environment. The first half of the chapter is focused on Si nanowire growth, and reviews diameter-dependent growth rate and orientation effects, metal catalysts, intentional doping, and the growth of Si_1-xGe_x nanowires and axial heterostructures. The second half is devoted to a review of III-V nanowire growth with an emphasis on GaAs and InAs nanowires. The growth of vertical and planar III-V nanowires is initially discussed, followed by doping and the synthesis of nanowire axial and radial (core-shell) heterostructures.