A study on gold-black coated a-Si:H microbolometer modelling

We present an optical-electrothermal model comparing gold-black, SiO 2 and Si 3 N 4 /SiO 2 absorbers in hydrogenated amorphous-silicon (a-Si:H) microbolometers. Layer-resolved absorption, continuous-current self-heating and same-frequency responsivity and noise calculations are combined. Under a 293 K background, a 5 K sensor-temperature-rise cap and a nominal 10 ms time-constant limit, selected gold-black candidates yield predicted detectivities of 2.635 × 10⁹ and 3.147 × 10⁹ cm√Hz W⁻ 1 at 30 Hz in the 8–15 µm and 3–5 µm bands, respectively. Ratios to the best dielectric candidates are 2.97 and 5.17 for independently varied devices, decreasing to 1.44 and 2.88 at common pixel and sensing-film dimensions. Numerical checks support implementation consistency. These conditional Johnson- and thermal-link-noise-limited predictions lack experimental validation, calibrated low-frequency/readout noise and established fabrication feasibility.