Elastically strain-sharing nanomembranes: flexible and transferable strained silicon and silicon–germanium alloys

Abstract

The emerging field of strained-Si based nanomembranes is reviewed, including fabrication techniques, strain-induced band structure engineering, electronic applications and three-dimensional membrane architectures. Elastic strain sharing between thin heteroepitaxial Si and SiGe films, enabled by techniques that allow release of these films from a handling substrate, creates a new material: freestanding, single-crystal, strained nanomembranes. These flexible nanomembranes are virtually dislocation-free and have many potential new applications. Strain engineering also provides opportunities for massively parallel self-assembly of a wide variety of three-dimensional nanostructures.

Direct-bandgap light-emitting germanium in tensilely strained nanomembranes

“…Ge NMs, which are based on a fabrication technology that has been developed in recent years for a wide range of applications (5)(6)(7)(8)(22)(23)(24)(25)(26)(27)(28), offer another perspective. With this technology, free-standing NMs are produced that can be readily transferred and bonded onto a flexible host substrate and then mechanically stretched.…”

Semiconductor Nanomembrane-Based Light-Emitting and Photodetecting Devices

“…It is found under tensile strain that the three vibration mode peaks of pentacene have shifted under the bending condition. According to the study that the Raman peak shift is related to the mobility improvement of pentacene [58,59], this photocurrent enhancement under the bending condition could be explained by the mobility improvement, given that tensile strain on the crystal lattice could increase the carriers' mobility of Si NM, as well [6,60]. To investigate the cause for this improved photocurrent and external quantum efficiency, the Raman confocal microscope is used to reflect the strain effect of the two materials.…”

3D heterostructures and systems for novel MEMS/NEMS

“…The buckled shape results from the simple elongation of the released films in the direction along the edge [12]. This technology is being further developed by many research groups [13][14][15].…”