Design and Fabrication of Thermopile Infrared Detector Based on Carbon Black Nanoparticle Absorption Layer

This study demonstrates a high-performance thermopile infrared detector that incorporates a carbon black nanoparticle (CBNP) absorption layer. To overcome the limitations associated with conventional infrared-absorbing materials—including high cost, complex fabrication, and constrained spectral response—a highly porous CBNP thin-film absorption layer was deposited onto the thermopile sensing area using inkjet printing. Combined with an optimized microcavity design, this approach significantly enhances the photothermal conversion efficiency of the device. Experimental results indicate that the detector equipped with the CBNP absorption layer achieves a responsivity of 47.9 V/W and a detectivity of 1.14 × 108 cm·Hz1/2·W−1. These values represent improvements of 34.55% in responsivity and 34.28% in detectivity, respectively, compared to a reference device without the CBNP layer. This work provides a promising strategy for the development of low-cost yet high-performance infrared detectors.