High-sensitivity bolometers from self-oriented single-walled carbon nanotube composites

Area of Science:

• Materials Science
• Nanotechnology
• Physics

Background:

• Carbon nanotubes (CNTs) are promising materials for infrared (IR) detection due to their unique thermal and electrical properties.
• Bolometric detectors offer high sensitivity and operate at room temperature, making them attractive for various sensing applications.

Purpose of the Study:

• To characterize the thermal and electrical properties of horizontally aligned single-walled carbon nanotube (SWCNT) films.
• To evaluate the bolometric performance of SWCNT films for potential use in IR detectors.
• To compare the obtained performance metrics with previously reported values for CNT-based bolometers.

Main Methods:

• Fabrication of horizontally aligned single-walled carbon nanotube films.
• Thermal characterization to determine the thermal time constant.
• Electrical characterization to measure the temperature coefficient of resistance (TCR).
• Measurement of voltage responsivity and detectivity at room temperature.

Main Results:

• An average thermal time constant (τ) of 420 μs was achieved.
• A temperature coefficient of resistance (TCR) of -2.94% K⁻¹ was obtained.
• Maximum voltage responsivity (R(V)) reached 230 V/W and maximum detectivity (D*) was 1.22 × 10⁸ cm Hz¹/² W⁻¹.
• These performance metrics surpass previously reported values for CNT films at room temperature.
• Maximum detectivity was observed at an operating frequency of 1.25 kHz.

Conclusions:

• Horizontally aligned SWCNT films exhibit excellent bolometric performance.
• The achieved TCR and responsivity indicate significant potential for sensitive IR detection applications.
• These findings establish a new benchmark for CNT-based bolometers, paving the way for advanced infrared sensing technologies.