SILICON NANOWIRES AND NANOWIRE HETEROSTRUCTURES

Silicon nanowires (SiNWs) and nanowire heterostructures are unique form of nanosilicon, which are grown by direct synthesis (bottom-up) rather than conventional lithography patterning (top-down) approach. Here we review key advances in SiNWs and SiNW heterostructures enabled by the bottom-up approach to nanoscience. First, we introduce a general method for the synthesis of SiNWs with precisely controlled physical dimensions and electronic properties, which is based on metal nanocluster catalysed vapour–liquid–solid growth. Second, we discuss fundamental low-temperature electrical transport studies that define key differences between our bottom-up SiNWs and top-down silicon nanostructures. Third, we describe the use of SiNWs as fundamental building blocks for a wide range of nanoscale electronic devices and circuits. Fourth, we describe rational strategies for large-scale hierarchical assembly of SiNWs and applications of unique assembly characteristics for macroelectronics. Fifth, we examine the potential of SiNWs as active elements in ultra-sensitive nanoscale sensors for chemical and biological detection. Last, we discuss SiNW heterostructures, which open up new and often unique dimensions of complexity and functionality.