The study reports a highly efficient and broadband plasmonic absorber that can absorb light over a wide range of wavelengths from 400 nm to 10 μm, achieving an average measured absorbance of approximately 99%. This absorber is fabricated through self-assembly of gold nanoparticles onto a nanoporous template using a one-step deposition process. The combination of efficient light absorption, strong field enhancement, and porous structures enables significant local heating and continuous stream flow, leading to over 90% efficiency in solar steam generation under a solar irradiation of only 4-sun intensity (4 kW m⁻²). The plasmonic absorber's performance is superior to other reported structures, including carbon nanotube-based absorbers, and its scalability and high-throughput self-assembly process make it suitable for large-scale manufacturing of nanophotonic structures and devices. The study also highlights the potential applications of this absorber in solar desalination and sterilization.The study reports a highly efficient and broadband plasmonic absorber that can absorb light over a wide range of wavelengths from 400 nm to 10 μm, achieving an average measured absorbance of approximately 99%. This absorber is fabricated through self-assembly of gold nanoparticles onto a nanoporous template using a one-step deposition process. The combination of efficient light absorption, strong field enhancement, and porous structures enables significant local heating and continuous stream flow, leading to over 90% efficiency in solar steam generation under a solar irradiation of only 4-sun intensity (4 kW m⁻²). The plasmonic absorber's performance is superior to other reported structures, including carbon nanotube-based absorbers, and its scalability and high-throughput self-assembly process make it suitable for large-scale manufacturing of nanophotonic structures and devices. The study also highlights the potential applications of this absorber in solar desalination and sterilization.