Transport and optical response of single nanowires

Semiconductor nanowires exhibit interesting optical and electronic properties which makes them useful in device applications. An important advantage of nanowires over other low dimensional structures is that nanowires can function as both active elements and as interconnects. Hence, it is essential to develop an understanding of their electrical and optical properties to define future applications. In order to explore the diverse and exciting opportunities in 1D system, it is critical to synthesize materials for which the chemical composition, diameter, length, as well as their optical and electronic properties can be effectively controlled. This review highlights our research activities in the growth, characterization, and device development aspect of semiconductor nanowires. Vapor–Liquid–Solid growth was used to fabricate high quality II–VI and III–V nanowires. We report on photoluminescence measurements on arrays of such nanowires, used as a means for optimizing their properties, and we show how optimized nanowires dominated by band-edge-related emissions can be prepared. Lithographic processing of individual nanowires was used to study their electrical and optical properties, from which we inferred resistivity, specific contact resistivity, and spectral photocurrent responsivity of ZnSe nanowires, and the carrier concentration, mobility, and dominant scattering mechanism for majority carriers (electrons) in ZnO:Mn nanowires. We also discuss preliminary potential measurements on individual nanowires performed using scanning Kelvin probe microscopy.