Ultrafast femtosecond laser processing for broadband emitters

We demonstrated laser-induced broadband emitters (LIBEs) with spectral emissivity higher than 0.96 from 0.3 um to 15 um wavelength to increase thermal radiative energy transport. Localized material removal induced by ultrafast femtosecond laser irradiation results in the hierarchical formation of microstructures decorated with micro-/nano- particles, leading to an exceptional enhancement in a spectral absorptivity on different types of substrates. Finite-difference time-domain simulations validated the effects of surface topology on the experimentally measured absorptivity. Moreover, LIBEs maintain their enhanced spectral absorptivity of 0.92 after heating at elevated temperatures for over 100 hours. Our results provide new insights into the use of ultrafast laser-matter interactions in cutting-edge energy harvesting and thermal management applications.