Greatly enhanced infrared normal spectral emissivity of microstructured silicon using a femtosecond laser

Abstract The infrared normal spectral emissivity of microstructured silicon prepared by femtosecond laser irradiation in SF 6 was measured for the wavelength range 2.5 μm to 25 μm. Greatly enhanced emissivity compared to that of flat silicon was observed over the entire wavelength range. For a sample with 13–14 μm high spikes, the emissivity at a temperature of 100 °C is approximately 0.96. The emissivity decreases slightly in the wavelength region above 8 μm, but remains higher than 0.9 over most of the measured wavelength range. Also the average emissivity is less than Nextel- Velvet-811-21 Coating , it can be used stably at more wide temperatures from 100 °C to 400 °C. These results show the potential for microstructured silicon to be used as a flat blackbody source or silicon-based pyroelectric and microbolometer devices.