title: Bandgap control using strained beam structures for Si photonic devices.
abstract: We have demonstrated that bandgap energy of Si can be controlled by micro-mechanically structured Si beams (250 nm thick, 3 μm wide, and 15 μm long) elastically deformed by an external force. Microscopic photoluminescence spectroscopy reveals that downward bending of the beam by 3 μm reveals a red shift in the peak from ~1100 nm up to ~1300 nm. It is found from calculations based on deformation potentials and finite element method that tensile strain as large as ~1.5% is generated in the top surface of the deformed beam and responsible for the red shift of the peak. The presented result should be a proof of concept to cancel wavelength fluctuation unavoidably occurring on uncooled LSIs in terms of stress application, and thereby an enabler of wavelength division multiplexing implementation on a chip. The applications of other beam materials such as Ge and GaAs are discussed.
authors.affiliation: Department of Materials Engineering, the University of Tokyo, 7-3-1, Hongo Bunkyo, Tokyo 113-8656, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Yoshimoto
authors.forename: Ryota
authors.initials: R
authors.lastname: Suzuki
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Ishikawa
authors.forename: Kazumi
authors.initials: K
authors.lastname: Wada
mesh_terms: D055119:Elastic Modulus; D004867:Equipment Design; D019544:Equipment Failure Analysis; D055096:Optical Devices; D012031:Refractometry / Q000295:instrumentation*; D012825:Silicon / Q000737:chemistry*; D013314:Stress, Mechanical; D013718:Tensile Strength; D014159:Transducers
chemical_list: D012825:Silicon