Coupled mechanical and optoelectronic characterization on sheared Si thin film

Strain engineering of semiconductors presents an enormous potential to vary their electronic properties by modifying their electronic bands, charge carrier population and mobility, bandgap, etc. It opens new roads to e.g. improve the speed of solid-state data transfer by providing direct bandgap light emitters for optical interconnections, to enhance the drive current and cut-off frequencies of MOSFET transistors. While tension is the classically used loading mode, pure shear has a more pronounced effect on the bandgap of silicon as revealed by ab-inito DFT calculations. A challenge in deforming thin films under pure shear is to experimentally characterize at the nanoscale the strain field of the deformed area which has to be similar to the film thickness. This proposal concerns the use of nano-diffraction strain mapping technique available at ID01 to link the mechanical and optoelectronic properties of strain engineered Si. This work will pave the way toward Ge strain engineering.