Single crystalline InGaAs nanopillar grown on polysilicon with dimensions beyond the substrate grain size limit.

摘要: Monolithic integration of III–V optoelectronic devices with materials for various functionalities inexpensively is always desirable. Polysilicon (poly-Si) an ideal platform because it dopable and semiconducting, can be deposited patterned easily on a wide range low cost substrates. However, the lack crystalline coherency in poly-Si poses immense challenge high-quality epitaxial growth. In this work, we demonstrate, first time, direct growth micrometer-sized InGaAs/GaAs nanopillars polysilicon. Transmission electron microscopy shows that pillars are single-crystalline pure wurzite-phase, far exceeding substrate crystal grain size ∼100 nm. The high quality enabled by unique tapering geometry at base nanostructure, which reduces effective InGaAs/Si contact area to <40 nm diameter. small footprint not only stress due lattice mismatch but also prevents nanopillar from nucleating multiple...