Studying and exploiting solid state dewetting of semiconductor thin films for flexible photonics

Solid state dewetting (SSD) is a natural shape instability occurring in thin solid films when heated at high temperature: it transforms a flat layer in isolated islands. SSD can be efficiently exploited in several fields, including flexible photonics, photocatalysis or dielectric Mie resonator, to form perfectly ordered and complex nano-architectures over large scales, as well as randomly organized, isolated islands. Among the dewetting systems reported in literature, in our group SiGe dewetting, i.e. SiGe structures directly formed on an electrically insulating and optically transparent substrate, has been efficiently exploited to realize arrays of nanostructures with footprint ranging from few nm up to several μm. Additionally, dewetting of Ge, which is of particular interest for photonic devices working at near and mid-infrared frequency, has recently started to be investigated. This work purpose is to study dewetted SiGe and Ge islands and to exploit them to produce flexible films for photonic sensing applications. In particular, also an innovative approach to transfer SiGe and Ge dewetted islands into a flexible substrate such as polydimethylsiloxane (PDMS) will be presented.