Nanowire Growth without Catalysts: Applications and Mechanisms at the Atomic Scale

Nanowire synthesis without catalyst offers a simple technique for efficient growth of pure nanowires, which provides a number of advanced applications. If catalyst particles are not utilized, there are many open questions, related to nanowire formation and growth mechanisms. Such questions limit the possibility to control the growth and nanowire structure, therefore hindering their wide range of applications. This review is devoted to the noncatalytic synthesis of nanowires and studies of their formation mechanisms by the means of the in situ transmission electron microscopy technique shedding light on the atomic scale dynamics during the growth, which is crucial for nanowire structure control. Furthermore, catalyst-free nanowires are analyzed in terms of future prospects for optoelectronic applications.