Room-Temperature Bolometric Response in Nitro-Boosted rGO

Area of Science:

• Materials Science
• Nanotechnology
• Sensor Technology

Background:

• Graphene-based bolometers are promising for thermal imaging and infrared detection due to their potential for high temperature coefficient of resistance (TCR) and fast response times.
• Pristine graphene exhibits weak electron-phonon interactions at room temperature, limiting its sensitivity and temperature dependence of resistance.
• Developing sensitive room-temperature graphene bolometers requires overcoming the challenge of suppressed electron-phonon scattering.

Purpose of the Study:

• To propose and demonstrate a flexible microbolometer based on a reduced graphene oxide (rGO) and chitosan (CS) hybrid for room-temperature operation.
• To investigate the role of nitrogen functional groups and defect-assisted scattering in enhancing the bolometric response.
• To improve the TCR, current responsivity, and response time of graphene-based bolometers.

Main Methods:

• Fabrication of a flexible microbolometer using a reduced graphene oxide (rGO) and chitosan (CS) hybrid.
• Chitosan treatment to enhance nitrogen functional groups in rGO, creating defect centers for supercollision scattering.
• Characterization of the microbolometer's performance, including TCR, current responsivity, and thermal response time near room temperature.

Main Results:

• The rGO-CS hybrid microbolometer demonstrated a significant bolometric response at room temperature.
• Nitrogen functional groups introduced via chitosan treatment promoted defect-assisted electron-phonon scattering (supercollision scattering), enhancing sensitivity.
• Achieved a maximum TCR of ~3.1%/K, current responsivity of ~10.84 μA/W, and millisecond-range thermal response time.

Conclusions:

• The developed nitro-boosted rGO-CS microbolometer effectively overcomes the limitations of weak electron-phonon interactions at room temperature.
• Chitosan enhances nitrogen functionality and provides flexibility, leading to improved TCR and durability.
• This work presents a novel pathway for high-performance room-temperature bolometers utilizing nitrogen-driven supercollision scattering in rGO-CS hybrids.