Rational Control of GeSn Nanowires

Research on Si compatible direct bandgap semiconductors is a hot topic due to the high demand of Si compatible optoelectronics. The group IV compounds, namely GeSn, has been studied extensively in its different forms: thin films, nanowires (NWs), and nanocrystals. Importantly, the attention being paid to GeSn NWs has increased in recent years thanks to two key factors: 1) better crystalline quality due to an easier strain relaxation in NWs; and 2) extraordinary Sn content (up to 30 at.%) associated to a very fast NW growth (>20 nm s⁻¹). Therefore, to effectively control the growth of GeSn NWs is a key issue for a practical application. Herein, various control aspects including the nature of the catalysts, the morphology of the NWs, and their Sn content are presented.