ARCHIVES In-fiber Semiconductor Filament Arrays

One-dimensional nanostructures with high aspect-ratios and nanometer cross-sectional dimensions have been the focus of recent studies in the persistent drive to minia-turize devices. Conventional bottom-up methods such as vapor-liquid-solid growth have been widely applied for the fabrication of uniform and high quality nanowires. Two challenges toward nanoelectronics and other applications remain: on the single-nanowire level, precisely manipulating an individual nanowire for the sophisticated functionalities, and on the multiple-nanowire level, integrating nanowires into de-signed architecture at large scale. Thus, an alternative approach with the capacity to achieve ordered and extended nanowires is highly desirable. In this thesis, we observe an intriguing phenomenon that a cylindrical shell upon reaching a characteristic thickness breaks up into filament arrays during optical-fiber thermal drawing. This structural evolution occurs exclusively in the cross-sectional plane, while the uniformity along the axial direction remains intact. We demon-strate crystalline semiconductor nanowires by post-drawing annealing procedure an