Highly effective strain-induced band-engineering of (111) oriented, direct-gap GeSn crystallized on amorphous SiO2 layers

作者：Li Haofeng; Wang Xiaoxin; Liu Jifeng^*

来源：Applied Physics Letters, 2016, 108(10): 102101.

DOI：10.1063/1.4943192

We demonstrate highly effective strain-induced band-engineering of (111) oriented direct-gap Ge1-xSnx thin films (0.074 < x < 0.085) crystallized on amorphous SiO2 towards 3D photonic integration. Due to a much smaller Poisson's ratio for (111) vs. (100) orientation, 0.44% thermally induced biaxial tensile strain reduces the direct-gap by 0.125 eV towards enhanced direct-gap semiconductor properties, twice as effective as the tensile strain in Ge(100) films. Correspondingly, the optical response is extended to lambda = 2.8 mu m. A dilatational deformation potential of a = -12.8 +/- 0.8 eV is derived. These GeSn films also demonstrate high thermal stability, offering both excellent direct-gap optoelectronic properties and fabrication/operation robustness for integrated photonics.

• 出版日期2016-3-7