Long Period Grating Modified with Quasi-2D Perovskite/PAN Hybrid Nanofibers for Relative Humidity Measurement

Area of Science:

• Materials Science
• Nanotechnology
• Sensor Technology

Background:

• Metal halide perovskites show promise for photodetectors but suffer from instability in oxygen and moisture.
• Developing stable and sensitive humidity sensors is crucial for practical applications.

Purpose of the Study:

• To fabricate a long-period grating (LPG) humidity sensor using moisture-sensitive quasi-2D perovskite nanocrystals.
• To investigate the sensor's performance based on humidity-induced changes in perovskite complex permittivity.

Main Methods:

• In situ synthesis and electrospinning of pure-bromide quasi-2D perovskite nanocrystals within a polyacrylonitrile (PAN) matrix.
• Fabrication of a perovskite/PAN hybrid nanofibers film on a fiber grating.
• Analysis of transmission spectrum changes (resonant amplitude and wavelength) in response to humidity variations.

Main Results:

• The LPG sensor exhibited an intensity sensitivity of approximately 0.21 dB/%RH.
• A wavelength sensitivity of about 18.2 pm/%RH was achieved in the 50-80% relative humidity range.
• The sensor demonstrated good performance in detecting humidity.

Conclusions:

• The proposed LPG sensor effectively utilizes the moisture sensitivity of perovskite nanocrystals for humidity sensing.
• The hybrid nanofiber structure offers a promising approach for developing stable and efficient humidity sensors.
• This technology holds potential for various humidity-sensing applications.