Optical metal-oxide tunnel detectors with microstructured electrodes

Area of Science:

• Optoelectronics and Nanophotonics

Background:

• Metal-oxide-metal (MOM) detectors are crucial for optoelectronic applications.
• Improving their quantum efficiency in the visible spectrum remains a key challenge.

Purpose of the Study:

• To significantly enhance the quantum efficiency of MOM detectors in the visible spectrum.
• To explore novel nanostructuring techniques for improved light-matter interaction.

Main Methods:

• Fabricating MOM detectors on silica substrates with periodically patterned bumps (approx. 0.25 microm separation).
• Utilizing nanostructured metallic films to excite localized plasma resonances and surface-plasmon polariton modes.
• Characterizing device performance, including voltage responsivity.

Main Results:

• Achieved an order-of-magnitude improvement in quantum efficiency for MOM detectors in the visible range.
• Demonstrated voltage responsivities of 5 mV/W into a 50-Omega impedance in preliminary devices.
• Observed enhanced light coupling due to plasmonic effects.

Conclusions:

• Periodic nanostructuring of substrates and metallic films is highly effective for boosting MOM detector performance.
• The demonstrated approach offers a pathway to highly sensitive and fast visible-light detectors.
• Potential for subpicosecond response times in optimized detector geometries.