Sub-micron pixel polarization-sensitive photodetector based on silicon nanowire

Area of Science:

• Optoelectronics
• Nanotechnology
• Materials Science

Background:

• Silicon nanowires are explored for polarization-sensitive applications.
• Understanding the mechanism of polarization response in silicon nanowires is crucial.

Purpose of the Study:

• To investigate the polarization-sensitive characteristics of sub-micron metal-single silicon nanowire-metal photodetectors.
• To elucidate the underlying mechanism of optical anisotropy in silicon nanowires.

Main Methods:

• Fabrication of sub-micron metal-single silicon nanowire-metal photodetectors.
• Characterization of photocurrent response under polarized light.
• Utilizing polarizing light microscopy and simulation to verify resonance enhancement.
• Performing Stokes parameter measurements and imaging.

Main Results:

• The photodetector exhibited polarization-sensitive characteristics with an anisotropic photocurrent ratio of 1.59 at 780 nm.
• Excellent responsivity (24.58 mA/W) and high detectivity (8.88 × 10^9 Jones) were achieved at 980 nm.
• Optical anisotropy was attributed to resonance enhancement, confirmed by microscopy and simulation.

Conclusions:

• The study demonstrates the potential of silicon nanowires for polarization-sensitive light detection.
• The findings provide a foundation for developing integrated, cost-effective on-chip polarization-sensitive optical chips using mature silicon processing.
• This work advances the development of advanced optical sensing technologies.