The formation of GeSn nanostructures catalyzed by Sn surface droplets during the growth of Ge1-xSnx/Ge/Si(001) heterostructures provide a promising strategy for the growth of high-quality Sn-containing group-IV alloys. The droplet formation is favored by Sn segregation at dislocation cores and diffusion of Sn towards the sample surface. Subsequent Sn droplet motion along 〈110〉 crystallographic directions result in self-assembled Ge stripes along the droplet’s path. A novel phenomenon is observed, for which Sn-rich GeSn nanowires (NWs) were periodically formed on top of Ge(Sn) stripes. While the front edge of the liquid Sn droplet is continuously moving and dissolving the Ge1-xSnx epilayer, the phenomenon of NW periodicity is explained by discrete jumping of the back edge of the droplet resulting in redeposition of material forming the NWs. It is also demonstrated that sn-induced phase separation of metastable Ge1-xSnx epilayers leads to carrier redistribution and an electric-field-induced conductivity type conversion from p- to n-type in the Ge(Sn) stripes. These results advance our understanding of the Sn segregation and phase separation mechanism for Ge1-xSnx epilayers at relatively low temperature (≥230 °C). This study could pave the way for understanding the droplet epitaxy synthesis of Sn-rich GeSn nanostructures generating emergent functionalities of GeSn-based nanodevices.