Large Area Nanohole Arrays for Sensing Fabricated by Interference Lithography

Area of Science:

• Nanofabrication
• Optical Sensing
• Materials Science

Background:

• Various nanofabrication techniques exist for sensor development.
• Existing methods like focused ion beam milling (FIB) and e-beam lithography (EBL) can be costly and time-consuming.
• There is a need for scalable and efficient methods for producing nano-patterned substrates.

Purpose of the Study:

• To explore interference lithography for fabricating large-area nanohole arrays in metal films.
• To optimize nanohole array parameters (size, periodicity, film thickness) for enhanced sensing performance.
• To evaluate the efficiency and sensitivity of interference lithography for bulk sensing applications.

Main Methods:

• Fabrication of large-area nanohole arrays using interference lithography.
• Characterization of transmission spectra of 1 cm² substrates.
• Systematic variation of hole size, periodicity, and film thickness.
• Bulk sensing experiments to determine sensitivity.

Main Results:

• Interference lithography successfully produced large-area nanohole arrays.
• Optimized arrays demonstrated high sensitivity for bulk sensing.
• Achieved sensitivity of approximately 1000 nm/RIU with visible range periodicity.
• Performance exceeded previously reported near-infrared (NIR) sensing capabilities.

Conclusions:

• Interference lithography is an efficient, flexible, and scalable method for nanohole array fabrication.
• This technique provides a cost-effective alternative to expensive and time-consuming nanofabrication methods.
• The developed nanohole arrays show significant potential for high-performance bulk sensing applications.