Laser-Driven Growth of Semiconductor Nanowires from Colloidal Nanocrystals via the Young-Laplace Effect

Abstract

The ability to produce nanowires through vapor- and solution-based processes has propelled nanowire material systems toward a wide range of technological applications. Conventional, vapor-based nanowire syntheses have enabled precise control over nanowire composition and phase. However, vapor-based nanowire growth employs batch processes with specialized pressure management systems designed to operate at high temperatures, limiting throughput. More recently developed solution-based nanowire growth processes have improved scalability but can require even more extensive pressure and temperature management systems. Here, we demonstrate a continuous-flow, solution-based nanowire growth process that utilizes the large Young-Laplace interfacial surface pressures and collective heating effects of colloidal metal nanocrystals under irradiation to drive semiconductor nanowire growth photothermally without the need for high-pressure or high-temperature equipment. In this process, a laser irradiates a solution containing metal nanocrystals and semiconductor precursors. Upon light absorption, the metal nanocrystals heat rapidly, inducing semiconductor precursor decomposition and nanowire growth. This process is performed on a benchtop in simple glassware under standard conditions. To demonstrate the generality of this technique, we synthesized three distinct semiconductor nanowire material systems: bismuth-seeded germanium nanowires, bismuth-seeded cadmium selenide nanowires, and indium-seeded germanium nanowires. The simplicity and versatility of this process opens the door to a range of experiments and technologies including in-line combinatorial identification of optimized reaction parameters, in situ spectroscopic measurements to study solution-based nanowire growth, and the potential production of nanowires with complex compositions or rationally incorporated dopants.