Nanowire-based devices combining light guiding and photodetection

Abstract

We demonstrate bridged nanowires on a non-single-crystal substrate as a versatile fabrication approach to combine active and passive photonic functionalities on silicon platforms. Silicon nanowires are grown on vertical non-single-crystal surfaces by a vapor-liquid-solid process and bridge a microtrench obtained by etching an amorphous optical rib waveguide. A pair of phosphorous-doped polysilicon electrodes is deposited on the walls of the waveguide microtrench for seeding the nanowire synthesis and for electrical interfacing. The bridged nanowires act as photoconductors and their photoresponse to edge-illumination from waveguided light is characterized. Taking advantage of crystalline nanowire growth on non-single-crystal substrates may ultimately lead to substrate-independent integration of best-of-breed semiconductor nanodevices for applications such as photonic integrated circuits